Model cannot be correctly instantiated by the Use API on Prod and stage intermittently

[Amsalek4]

Hi Team,

In cloud, We are facing the below issue recently on prod and stage alone intermittently. Its showing Identifier com.allb2bsites.core.models.PageHeadModel cannot be correctly instantiated by the Use API

Its working on dev and local perfectly. we haven't done any code change on this model class recently. 

This model has been calling in page component so none of the pages are  loading and giving internal server error. I am seeing some other model class also throwing this error in xf .  We couldn't find anything apart from this error from logs. Java :11 , Both author and publisher

Model Code:

@Model(adaptables = {SlingHttpServletRequest.class}, adapters = PageHeadModel.class, defaultInjectionStrategy = DefaultInjectionStrategy.OPTIONAL)
public class PageHeadModelImpl implements PageHeadModel {


    private final Logger log = LoggerFactory.getLogger(PageHeadModelImpl.class);
    private Map<String, String> languages;

    @ScriptVariable
    private Page currentPage;

    @OSGiService
    private customservice customservice;

    @OSGiService
    private Externalizer externalizer;

    @SlingObject
    private ResourceResolver resourceResolver;

    @Self
    private SlingHttpServletRequest slingRequest;

Another  model which gave this issue:

Model(adaptables = { SlingHttpServletRequest.class },
adapters =  SimpleNavModel.class,  resourceType = {SimpleNavModelImpl.RESOURCE_TYPE},
defaultInjectionStrategy = DefaultInjectionStrategy.OPTIONAL)
public  class SimpleNavModelImpl implements SimpleNavModel {

protected static final String RESOURCE_TYPE = "xxxx/components/content/simple-nav/v1/simple-nav";

    @ChildResource
    private List<SimpleNavItemModel> simpleNavItems;

    @Override
    public List<SimpleNavItemModel> getSimpleNavItems() {
        if(simpleNavItems != null) {
            return new ArrayList<>(simpleNavItems);
        }
        return new ArrayList<>();
    }
}

15.05.2024 14:47:04.283 [cm-p103058-e972759-aem-publish-85c697b46b-mc865] *ERROR* [[::1] [1715784414341] GET /content/businesstravel/pt/hotel-subscription-cards/all-plus-voyageur.html HTTP/1.1] org.apache.sling.engine.impl.SlingRequestProcessorImpl service: Uncaught SlingException
org.apache.sling.scripting.sightly.SightlyException: Identifier com.allb2bsites.core.models.PageHeadModel cannot be correctly instantiated by the Use API
at org.apache.sling.scripting.sightly.impl.engine.extension.use.UseRuntimeExtension.call(UseRuntimeExtension.java:76) [org.apache.sling.scripting.sightly:1.4.20.140]
at org.apache.sling.scripting.sightly.impl.engine.runtime.RenderContextImpl.call(RenderContextImpl.java:72) [org.apache.sling.scripting.sightly:1.4.20.140]
at org.apache.sling.scripting.sightly.apps.allbbsites.components.structure.page.page__002e__html.render(page__002e__html.java:53)
at org.apache.sling.scripting.sightly.render.RenderUnit.render(RenderUnit.java:53) [org.apache.sling.scripting.sightly.runtime:1.2.6.140]
at org.apache.sling.scripting.sightly.impl.engine.SightlyCompiledScript.eval(SightlyCompiledScript.java:61) [org.apache.sling.scripting.sightly:1.4.20.140]
at org.apache.sling.scripting.core.impl.DefaultSlingScript.call(DefaultSlingScript.java:393) [org.apache.sling.scripting.core:2.4.8]
at org.apache.sling.scripting.core.impl.DefaultSlingScript.eval(DefaultSlingScript.java:191) [org.apache.sling.scripting.core:2.4.8]
at org.apache.sling.scripting.core.impl.DefaultSlingScript.service(DefaultSlingScript.java:500) [org.apache.sling.scripting.core:2.4.8]
at org.apache.sling.engine.impl.request.RequestData.service(RequestData.java:545) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.filter.SlingComponentFilterChain.render(SlingComponentFilterChain.java:45) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:88) [org.apache.sling.engine:2.15.10]
at com.ace.core.filters.ResponseCacheFilter.doFilter(ResponseCacheFilter.java:119) [acelibrary.core:2024.515.1125921.0004142516]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.ace.core.filters.ResponseCacheFilter.doFilter(ResponseCacheFilter.java:119) [acelibrary.core:2024.515.1125921.0004142516]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.day.cq.wcm.core.impl.WCMDebugFilter.doFilter(WCMDebugFilter.java:138) [com.day.cq.wcm.cq-wcm-core:5.14.150]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at org.apache.sling.dynamicinclude.IncludeTagFilter.doFilter(IncludeTagFilter.java:71) [org.apache.sling.dynamic-include:3.1.2]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.adobe.acs.commons.granite.ui.components.impl.include.IncludeDecoratorFilterImpl.doFilter(IncludeDecoratorFilterImpl.java:92) [com.adobe.acs.acs-aem-commons-bundle:5.3.4]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.adobe.granite.uriprovider.dba.DBAHeaderFilter.doFilter(DBAHeaderFilter.java:107) [com.adobe.granite.uriprovider.dba:0.2.8]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.adobe.cq.dam.cfm.ui.impl.EditorCacheFilter.doFilter(EditorCacheFilter.java:102) [com.adobe.dam.cq-dam-cfm-impl:0.12.360]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.adobe.granite.metrics.knownerrors.impl.ErrorLoggingComponentFilter.doFilter(ErrorLoggingComponentFilter.java:71) [com.adobe.granite.metrics.knownerrors:0.0.24]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.day.cq.wcm.core.impl.monitoring.PageComponentRequestFilter.doFilter(PageComponentRequestFilter.java:105) [com.day.cq.wcm.cq-wcm-core:5.14.150]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.day.cq.wcm.core.impl.WCMComponentFilter.doFilter(WCMComponentFilter.java:278) [com.day.cq.wcm.cq-wcm-core:5.14.150]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.day.cq.wcm.core.impl.page.PageLockFilter.doFilter(PageLockFilter.java:91) [com.day.cq.wcm.cq-wcm-core:5.14.150]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.day.cq.personalization.impl.TargetComponentFilter.doFilter(TargetComponentFilter.java:94) [com.day.cq.cq-personalization:5.13.58]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.adobe.granite.csrf.impl.CSRFFilter.doFilter(CSRFFilter.java:225) [com.adobe.granite.csrf:1.0.26]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.SlingRequestProcessorImpl.processComponent(SlingRequestProcessorImpl.java:367) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.SlingRequestProcessorImpl.dispatchRequest(SlingRequestProcessorImpl.java:416) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.request.SlingRequestDispatcher.dispatch(SlingRequestDispatcher.java:203) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.request.SlingRequestDispatcher.include(SlingRequestDispatcher.java:102) [org.apache.sling.engine:2.15.10]
at com.day.cq.wcm.core.impl.WCMComponentFilter$ForwardRequestDispatcher.include(WCMComponentFilter.java:516) [com.day.cq.wcm.cq-wcm-core:5.14.150]
at org.apache.jsp.libs.cq.Page.Page__002e__jsp._jspService(Page__002e__jsp.java:117)
at org.apache.sling.scripting.jsp.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70) [org.apache.sling.scripting.jsp:2.6.0]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:764) [org.apache.felix.http.servlet-api:1.2.0]
at org.apache.sling.scripting.jsp.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:521) [org.apache.sling.scripting.jsp:2.6.0]
at org.apache.sling.scripting.jsp.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:464) [org.apache.sling.scripting.jsp:2.6.0]
at org.apache.sling.scripting.jsp.JspScriptEngineFactory$JspScriptEngine.callJsp(JspScriptEngineFactory.java:500) [org.apache.sling.scripting.jsp:2.6.0]
at org.apache.sling.scripting.jsp.JspScriptEngineFactory$JspScriptEngine.eval(JspScriptEngineFactory.java:582) [org.apache.sling.scripting.jsp:2.6.0]
at org.apache.sling.scripting.core.impl.DefaultSlingScript.call(DefaultSlingScript.java:395) [org.apache.sling.scripting.core:2.4.8]
at org.apache.sling.scripting.core.impl.DefaultSlingScript.eval(DefaultSlingScript.java:191) [org.apache.sling.scripting.core:2.4.8]
at org.apache.sling.scripting.core.impl.DefaultSlingScript.service(DefaultSlingScript.java:500) [org.apache.sling.scripting.core:2.4.8]
at org.apache.sling.engine.impl.request.RequestData.service(RequestData.java:545) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.filter.SlingComponentFilterChain.render(SlingComponentFilterChain.java:45) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:88) [org.apache.sling.engine:2.15.10]
at com.day.cq.wcm.core.impl.WCMDebugFilter.doFilter(WCMDebugFilter.java:138) [com.day.cq.wcm.cq-wcm-core:5.14.150]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.adobe.cq.dam.cfm.ui.impl.EditorCacheFilter.doFilter(EditorCacheFilter.java:102) [com.adobe.dam.cq-dam-cfm-impl:0.12.360]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.adobe.granite.metrics.knownerrors.impl.ErrorLoggingComponentFilter.doFilter(ErrorLoggingComponentFilter.java:71) [com.adobe.granite.metrics.knownerrors:0.0.24]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.day.cq.wcm.core.impl.monitoring.PageComponentRequestFilter.doFilter(PageComponentRequestFilter.java:105) [com.day.cq.wcm.cq-wcm-core:5.14.150]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.day.cq.wcm.core.impl.WCMComponentFilter.filterRootInclude(WCMComponentFilter.java:375) [com.day.cq.wcm.cq-wcm-core:5.14.150]
at com.day.cq.wcm.core.impl.WCMComponentFilter.doFilter(WCMComponentFilter.java:190) [com.day.cq.wcm.cq-wcm-core:5.14.150]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.day.cq.wcm.core.impl.page.PageLockFilter.doFilter(PageLockFilter.java:91) [com.day.cq.wcm.cq-wcm-core:5.14.150]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.day.cq.personalization.impl.TargetComponentFilter.doFilter(TargetComponentFilter.java:94) [com.day.cq.cq-personalization:5.13.58]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.SlingRequestProcessorImpl.processComponent(SlingRequestProcessorImpl.java:367) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.filter.RequestSlingFilterChain.render(RequestSlingFilterChain.java:49) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:88) [org.apache.sling.engine:2.15.10]
at org.apache.sling.dynamicinclude.SyntheticResourceFilter.doFilter(SyntheticResourceFilter.java:66) [org.apache.sling.dynamic-include:3.1.2]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.day.cq.dam.core.impl.assetlinkshare.AdhocAssetShareAuthHandler.doFilter(AdhocAssetShareAuthHandler.java:516) [com.day.cq.dam.cq-dam-core:5.15.104]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:84) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:84) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:84) [org.apache.sling.engine:2.15.10]
at com.day.cq.dam.core.impl.servlet.ActivityRecordHandler.doFilter(ActivityRecordHandler.java:141) [com.day.cq.dam.cq-dam-core:5.15.104]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.adobe.granite.requests.logging.impl.RequestLoggerImpl.doFilter(RequestLoggerImpl.java:135) [com.adobe.granite.requests.logging:1.0.22]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.adobe.granite.rest.impl.servlet.ApiResourceFilter.doFilter(ApiResourceFilter.java:70) [com.adobe.granite.rest.api:1.1.42]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.adobe.granite.rest.assets.impl.AssetContentDispositionFilter.doFilter(AssetContentDispositionFilter.java:96) [com.adobe.granite.rest.assets:1.0.74]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.day.cq.wcm.core.impl.AuthoringUIModeServiceImpl.doFilter(AuthoringUIModeServiceImpl.java:385) [com.day.cq.wcm.cq-wcm-core:5.14.150]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.ace.core.filters.ResponseCacheFilter.doFilter(ResponseCacheFilter.java:119) [acelibrary.core:2024.515.1125921.0004142516]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.ace.core.filters.ResponseCacheFilter.doFilter(ResponseCacheFilter.java:119) [acelibrary.core:2024.515.1125921.0004142516]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.day.cq.wcm.mobile.core.impl.redirect.RedirectFilter.doFilter(RedirectFilter.java:248) [com.day.cq.wcm.cq-wcm-mobile-core:5.11.10]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.allb2bsites.core.filters.LoggingFilter.doFilter(LoggingFilter.java:58) [aem-allb2bsites-project.core:2024.515.1125921.0004142516]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:84) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:84) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:84) [org.apache.sling.engine:2.15.10]
at com.ace.core.filters.PageRedirectFilter.doFilter(PageRedirectFilter.java:74) [acelibrary.core:2024.515.1125921.0004142516]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.ace.core.filters.NotFoundPageFilter.doFilter(NotFoundPageFilter.java:67) [acelibrary.core:2024.515.1125921.0004142516]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:84) [org.apache.sling.engine:2.15.10]
at org.apache.sling.dynamicinclude.CacheControlFilter.doFilter(CacheControlFilter.java:67) [org.apache.sling.dynamic-include:3.1.2]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:84) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:84) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:84) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:84) [org.apache.sling.engine:2.15.10]
at com.ace.core.filters.PageRedirectFilter.doFilter(PageRedirectFilter.java:74) [acelibrary.core:2024.515.1125921.0004142516]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.ace.core.filters.NotFoundPageFilter.doFilter(NotFoundPageFilter.java:67) [acelibrary.core:2024.515.1125921.0004142516]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.adobe.granite.uriprovider.dba.DBAHeaderFilter.doFilter(DBAHeaderFilter.java:107) [com.adobe.granite.uriprovider.dba:0.2.8]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.adobe.cq.wcm.core.extensions.amp.internal.AmpModeForwardFilter.doFilter(AmpModeForwardFilter.java:95) [com.adobe.cq.core.wcm.components.extensions.amp:2.24.6]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.adobe.cq.wcm.core.components.internal.servlets.TableOfContentsFilter.doFilter(TableOfContentsFilter.java:122) [com.adobe.cq.core.wcm.components.core:2.24.6]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.day.cq.dam.core.impl.servlet.DisableLegacyServletFilter.executeFilter(DisableLegacyServletFilter.java:197) [com.day.cq.dam.cq-dam-core:5.15.104]
at com.day.cq.dam.core.impl.servlet.DisableLegacyServletFilter.doFilter(DisableLegacyServletFilter.java:154) [com.day.cq.dam.cq-dam-core:5.15.104]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.debug.RequestProgressTrackerLogFilter.doFilter(RequestProgressTrackerLogFilter.java:109) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:84) [org.apache.sling.engine:2.15.10]
at com.ace.core.filters.POSContextFilter.doFilter(POSContextFilter.java:168) [acelibrary.core:2024.515.1125921.0004142516]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.ace.core.filters.POSContextFilter.doFilter(POSContextFilter.java:168) [acelibrary.core:2024.515.1125921.0004142516]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.ace.core.pdp.filters.PDPAuthorModeFilter.doFilter(PDPAuthorModeFilter.java:117)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:84) [org.apache.sling.engine:2.15.10]
at com.ace.core.pdp.filters.PDPAuthorModeFilter.doFilter(PDPAuthorModeFilter.java:117)
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:84) [org.apache.sling.engine:2.15.10]
at com.day.cq.wcm.foundation.forms.FormsHandlingServletHelper.handleFilter(FormsHandlingServletHelper.java:226) [com.day.cq.wcm.cq-wcm-foundation:5.14.46]
at com.day.cq.wcm.foundation.forms.impl.FormsHandlingServlet.doFilter(FormsHandlingServlet.java:138) [com.day.cq.wcm.cq-wcm-foundation:5.14.46]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.adobe.granite.optout.impl.OptOutFilter.doFilter(OptOutFilter.java:76) [com.adobe.granite.optout:1.0.0]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.day.cq.wcm.foundation.forms.FormsHandlingServletHelper.handleFilter(FormsHandlingServletHelper.java:226) [com.day.cq.wcm.cq-wcm-foundation:5.14.46]
at com.adobe.cq.wcm.core.components.internal.servlets.CoreFormHandlingServlet.doFilter(CoreFormHandlingServlet.java:123) [com.adobe.cq.core.wcm.components.core:2.24.6]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.adobe.acs.commons.wcm.impl.AemEnvironmentIndicatorFilter$InnerEnvironmentIndicatorFilter.doFilter(AemEnvironmentIndicatorFilter.java:467) [com.adobe.acs.acs-aem-commons-bundle:5.3.4]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.day.cq.wcm.core.impl.WCMRequestFilter.doFilter(WCMRequestFilter.java:90) [com.day.cq.wcm.cq-wcm-core:5.14.150]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at org.apache.sling.rewriter.impl.RewriterFilter.doFilter(RewriterFilter.java:87) [org.apache.sling.rewriter:1.3.10]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.adobe.granite.httpcache.impl.InnerCacheFilter.doFilter(InnerCacheFilter.java:81) [com.adobe.granite.httpcache.core:1.0.8]
at com.adobe.granite.httpcache.impl.InnerCacheFilter.doFilter(InnerCacheFilter.java:60) [com.adobe.granite.httpcache.core:1.0.8]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at org.apache.sling.i18n.impl.I18NFilter.doFilter(I18NFilter.java:131) [org.apache.sling.i18n:2.6.2]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at com.adobe.granite.csrf.impl.CSRFFilter.doFilter(CSRFFilter.java:225) [com.adobe.granite.csrf:1.0.26]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at org.apache.sling.security.impl.ContentDispositionFilter.doFilter(ContentDispositionFilter.java:162) [org.apache.sling.security:1.2.0]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:84) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:84) [org.apache.sling.engine:2.15.10]
at com.adobe.granite.resourceresolverhelper.impl.ResourceResolverHelperImpl.doFilter(ResourceResolverHelperImpl.java:79) [com.adobe.granite.resourceresolverhelper:1.0.6]
at org.apache.sling.engine.impl.filter.AbstractSlingFilterChain.doFilter(AbstractSlingFilterChain.java:78) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.SlingRequestProcessorImpl.doProcessRequest(SlingRequestProcessorImpl.java:240) [org.apache.sling.engine:2.15.10]
at org.apache.sling.engine.impl.SlingMainServlet.service(SlingMainServlet.java:130) [org.apache.sling.engine:2.15.10]
at org.apache.felix.http.base.internal.handler.ServletHandler.handle(ServletHandler.java:127) [org.apache.felix.http.jetty:4.2.26]
at org.apache.felix.http.base.internal.dispatch.InvocationChain.doFilter(InvocationChain.java:86) [org.apache.felix.http.jetty:4.2.26]
at com.adobe.acs.commons.wcm.impl.AemEnvironmentIndicatorFilter.doFilter(AemEnvironmentIndicatorFilter.java:218) [com.adobe.acs.acs-aem-commons-bundle:5.3.4]
at org.apache.felix.http.base.internal.handler.FilterHandler.handle(FilterHandler.java:149) [org.apache.felix.http.jetty:4.2.26]
at org.apache.felix.http.base.internal.dispatch.InvocationChain.doFilter(InvocationChain.java:81) [org.apache.felix.http.jetty:4.2.26]
at com.adobe.granite.metrics.redimpl.REDMetricsServletFilter.doFilter(REDMetricsServletFilter.java:214) [com.adobe.granite.metrics.red:1.2.0]
at org.apache.felix.http.base.internal.handler.FilterHandler.handle(FilterHandler.java:149) [org.apache.felix.http.jetty:4.2.26]
at org.apache.felix.http.base.internal.dispatch.InvocationChain.doFilter(InvocationChain.java:81) [org.apache.felix.http.jetty:4.2.26]
at com.adobe.granite.metrics.knownerrors.impl.ReportingRequestFilter.doFilter(ReportingRequestFilter.java:100) [com.adobe.granite.metrics.knownerrors:0.0.24]
at org.apache.felix.http.base.internal.handler.FilterHandler.handle(FilterHandler.java:149) [org.apache.felix.http.jetty:4.2.26]
at org.apache.felix.http.base.internal.dispatch.InvocationChain.doFilter(InvocationChain.java:81) [org.apache.felix.http.jetty:4.2.26]
at com.adobe.granite.cors.impl.CORSFilter.doFilter(CORSFilter.java:94) [com.adobe.granite.cors:1.0.22]
at org.apache.felix.http.base.internal.handler.FilterHandler.handle(FilterHandler.java:149) [org.apache.felix.http.jetty:4.2.26]
at org.apache.felix.http.base.internal.dispatch.InvocationChain.doFilter(InvocationChain.java:81) [org.apache.felix.http.jetty:4.2.26]
at com.adobe.granite.license.impl.http.LicenseCheckFilter.doFilter(LicenseCheckFilter.java:301) [com.adobe.granite.license.http:1.0.0]
at org.apache.felix.http.base.internal.handler.FilterHandler.handle(FilterHandler.java:149) [org.apache.felix.http.jetty:4.2.26]
at org.apache.felix.http.base.internal.dispatch.InvocationChain.doFilter(InvocationChain.java:81) [org.apache.felix.http.jetty:4.2.26]
at org.apache.sling.i18n.impl.I18NFilter.doFilter(I18NFilter.java:131) [org.apache.sling.i18n:2.6.2]
at org.apache.felix.http.base.internal.handler.FilterHandler.handle(FilterHandler.java:149) [org.apache.felix.http.jetty:4.2.26]
at org.apache.felix.http.base.internal.dispatch.InvocationChain.doFilter(InvocationChain.java:81) [org.apache.felix.http.jetty:4.2.26]
at org.apache.sling.featureflags.impl.FeatureManager.doFilter(FeatureManager.java:116) [org.apache.sling.featureflags:1.2.2]
at org.apache.felix.http.base.internal.handler.FilterHandler.handle(FilterHandler.java:149) [org.apache.felix.http.jetty:4.2.26]
at org.apache.felix.http.base.internal.dispatch.InvocationChain.doFilter(InvocationChain.java:81) [org.apache.felix.http.jetty:4.2.26]
at org.apache.sling.engine.impl.log.RequestLoggerFilter.doFilter(RequestLoggerFilter.java:73) [org.apache.sling.engine:2.15.10]
at org.apache.felix.http.base.internal.handler.FilterHandler.handle(FilterHandler.java:149) [org.apache.felix.http.jetty:4.2.26]
at org.apache.felix.http.base.internal.dispatch.InvocationChain.doFilter(InvocationChain.java:81) [org.apache.felix.http.jetty:4.2.26]
at org.apache.sling.engine.impl.parameters.RequestParameterSupportConfigurer.doFilter(RequestParameterSupportConfigurer.java:67) [org.apache.sling.engine:2.15.10]
at org.apache.felix.http.base.internal.handler.FilterHandler.handle(FilterHandler.java:149) [org.apache.felix.http.jetty:4.2.26]
at org.apache.felix.http.base.internal.dispatch.InvocationChain.doFilter(InvocationChain.java:81) [org.apache.felix.http.jetty:4.2.26]
at org.apache.felix.http.base.internal.dispatch.Dispatcher$1.doFilter(Dispatcher.java:152) [org.apache.felix.http.jetty:4.2.26]
at org.apache.felix.http.base.internal.whiteboard.WhiteboardManager$2.doFilter(WhiteboardManager.java:992) [org.apache.felix.http.jetty:4.2.26]
at com.adobe.granite.ratelimit.AdaptiveRateLimitFilter.handleRequest(AdaptiveRateLimitFilter.java:465) [com.adobe.granite.ratelimit:5.0.4]
at com.adobe.granite.ratelimit.AdaptiveRateLimitFilter.doFilter(AdaptiveRateLimitFilter.java:407) [com.adobe.granite.ratelimit:5.0.4]
at org.apache.felix.http.base.internal.handler.PreprocessorHandler.handle(PreprocessorHandler.java:137) [org.apache.felix.http.jetty:4.2.26]
at org.apache.felix.http.base.internal.whiteboard.WhiteboardManager$2.doFilter(WhiteboardManager.java:998) [org.apache.felix.http.jetty:4.2.26]
at com.adobe.granite.auth.oauth.impl.OAuthCallbackFilter.doFilter(OAuthCallbackFilter.java:78) [com.adobe.granite.auth.oauth:1.10.30]
at org.apache.felix.http.base.internal.handler.PreprocessorHandler.handle(PreprocessorHandler.java:137) [org.apache.felix.http.jetty:4.2.26]
at org.apache.felix.http.base.internal.whiteboard.WhiteboardManager$2.doFilter(WhiteboardManager.java:998) [org.apache.felix.http.jetty:4.2.26]
at com.adobe.granite.auth.ims.impl.IMSClusterExchangeTokenPreprocessor.doFilter(IMSClusterExchangeTokenPreprocessor.java:241) [com.adobe.granite.auth.ims:1.4.54]
at org.apache.felix.http.base.internal.handler.PreprocessorHandler.handle(PreprocessorHandler.java:137) [org.apache.felix.http.jetty:4.2.26]
at org.apache.felix.http.base.internal.whiteboard.WhiteboardManager$2.doFilter(WhiteboardManager.java:998) [org.apache.felix.http.jetty:4.2.26]
at com.adobe.granite.cors.impl.CORSFilter.doFilter(CORSFilter.java:94) [com.adobe.granite.cors:1.0.22]
at org.apache.felix.http.base.internal.handler.PreprocessorHandler.handle(PreprocessorHandler.java:137) [org.apache.felix.http.jetty:4.2.26]
at org.apache.felix.http.base.internal.whiteboard.WhiteboardManager$2.doFilter(WhiteboardManager.java:998) [org.apache.felix.http.jetty:4.2.26]
at org.apache.sling.security.impl.ReferrerFilter.doFilter(ReferrerFilter.java:345) [org.apache.sling.security:1.2.0]
at org.apache.felix.http.base.internal.handler.PreprocessorHandler.handle(PreprocessorHandler.java:137) [org.apache.felix.http.jetty:4.2.26]
at org.apache.felix.http.base.internal.whiteboard.WhiteboardManager$2.doFilter(WhiteboardManager.java:998) [org.apache.felix.http.jetty:4.2.26]
at org.apache.felix.http.sslfilter.internal.SslFilter.doFilter(SslFilter.java:97) [org.apache.felix.http.sslfilter:1.2.6]
at org.apache.felix.http.base.internal.handler.PreprocessorHandler.handle(PreprocessorHandler.java:137) [org.apache.felix.http.jetty:4.2.26]
at org.apache.felix.http.base.internal.whiteboard.WhiteboardManager$2.doFilter(WhiteboardManager.java:998) [org.apache.felix.http.jetty:4.2.26]
at org.apache.sling.engine.impl.log.RequestLoggerPreprocessor.doFilter(RequestLoggerPreprocessor.java:47) [org.apache.sling.engine:2.15.10]
at org.apache.felix.http.base.internal.handler.PreprocessorHandler.handle(PreprocessorHandler.java:137) [org.apache.felix.http.jetty:4.2.26]
at org.apache.felix.http.base.internal.whiteboard.WhiteboardManager$2.doFilter(WhiteboardManager.java:998) [org.apache.felix.http.jetty:4.2.26]
at com.adobe.granite.probes.impl.ProbesPreprocessor.doFilter(ProbesPreprocessor.java:54) [com.adobe.granite.probes:1.0.16]
at org.apache.felix.http.base.internal.handler.PreprocessorHandler.handle(PreprocessorHandler.java:137) [org.apache.felix.http.jetty:4.2.26]
at org.apache.felix.http.base.internal.whiteboard.WhiteboardManager$2.doFilter(WhiteboardManager.java:998) [org.apache.felix.http.jetty:4.2.26]
at org.apache.felix.http.base.internal.whiteboard.WhiteboardManager.invokePreprocessors(WhiteboardManager.java:1002) [org.apache.felix.http.jetty:4.2.26]
at org.apache.felix.http.base.internal.dispatch.Dispatcher.dispatch(Dispatcher.java:94) [org.apache.felix.http.jetty:4.2.26]
at org.apache.felix.http.base.internal.dispatch.DispatcherServlet.service(DispatcherServlet.java:49) [org.apache.felix.http.jetty:4.2.26]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:764) [org.apache.felix.http.servlet-api:1.2.0]
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:799) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:554) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:233) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1624) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:233) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1440) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:188) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:505) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1594) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:186) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1355) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:191) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.server.handler.StatisticsHandler.handle(StatisticsHandler.java:181) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.server.Server.handle(Server.java:516) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.server.HttpChannel.lambda$handle$1(HttpChannel.java:487) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.server.HttpChannel.dispatch(HttpChannel.java:732) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:479) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:277) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:311) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:105) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.io.ChannelEndPoint$1.run(ChannelEndPoint.java:104) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:338) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:315) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:173) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:131) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:409) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:883) [org.apache.felix.http.jetty:4.2.26]
at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:1034) [org.apache.felix.http.jetty:4.2.26]
at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.lang.IllegalArgumentException: com.allb2bsites.core.models.PageHeadModel represents an interface or an abstract class which cannot be instantiated.
at org.apache.sling.scripting.sightly.impl.engine.extension.use.JavaUseProvider.loadObject(JavaUseProvider.java:215) [org.apache.sling.scripting.sightly:1.4.20.140]
at org.apache.sling.scripting.sightly.impl.engine.extension.use.JavaUseProvider.provide(JavaUseProvider.java:130) [org.apache.sling.scripting.sightly:1.4.20.140]
at org.apache.sling.scripting.sightly.impl.engine.extension.use.UseRuntimeExtension.call(UseRuntimeExtension.java:71) [org.apache.sling.scripting.sightly:1.4.20.140]
... 257 common frames omitted

@Kamal_Kishor @Mahesh_Gunaje  @sarav_prakash @arunpatidar @VeenaVikraman @Vijayalakshmi_S 

[sarav_prakash]

Hi @Amsalek4 I dont have an exact answer. But is weird, your issue is intermittent and works partially. 

If its code bug, all pages must 100% fail, cant be, works in dev; fails in prod. But could see you are missing some best practices 

1. PageModel is missing resourceType. Though optional annotation, if you have conditions to read resource, example, request.getResource(), its potential to fail conditionally
2. Happily add `implements Page` and adapters={Page.class, PageModel.class}. You can reuse from ootb interface, and maybe you dont need currentPage, since you are adapting already
3. SimpleNavModel component, dont see issues. But reduce adaptable={Resource.class}. Only if you think you need something from SlingServletRequest, extend its scope, else keep its scope simple to Resource. 
4. The @ChildResource is missing name. Its ok assuming your node name is same `simpleNavItems`. Incase some of your old pages had child nodes in different names and you refactored recently, it ll fail on those legacy pages. 

Once again, if above are really bugs, they must break all your pages consistently. Only possibility I could think is, you had recent refactor that works on new pages, but breaks on old pages. Try to package your production content into dev/local and try reproducing. Need to break first in local and then try fix to validate. 

[gkalyan]

Hi @Amsalek4 

As this issues seems to happening only in PROD/Stage but not on DEV/local and is intermittent.

The issue should with the AEM environment or the way the models are being instantiated,

rather than a problem with the model classes themselves, since you haven't made any recent changes to the code.

As this is intermittent, it can be caused by thread contention or memory issues, which can lead to race conditions. The other issue might be the differences in the configuration, deployment between stage and dev like some dependencies missing in the prod/stage which in local they are present.

Firstly, I would check the configurations first on both the instances to rule that out.

Second, check all the dependencies for this bundles are properly installed and running in stage/prod as in some cases they might installed but not running.

Hope this gives you some direction.

[Jörg_Hoh]

In the stacktrace there is this line:

Caused by: java.lang.IllegalArgumentException: com.allb2bsites.core.models.PageHeadModel represents an interface or an abstract class which cannot be instantiated

That means, that at some point the PageHeadModel (which is an interface! You posted the PageHeadModelImpl class) is tried to be instantiated, and that this is causing the problem.

Can you paste the relevant parts of /apps/allbbsites/components/structure/page/page.html?

[Amsalek4]

Hi @Jörg_Hoh  

Please find the page.html where we have included other html too.

<!DOCTYPE HTML>
<html data-sly-use.page="com.adobe.cq.wcm.core.components.models.Page" lang="${page.language.toLowerCase}"
  data-sly-use.pwa="com.adobe.cq.wcm.core.components.models.PWA" data-sly-use.head="head.html"
  data-sly-use.redirect="redirect.html" data-sly-use.hrefTemplate="href-langs.html"
  data-sly-use.model="com.allb2bsites.core.models.PageHeadModel">

<head data-sly-call="${head.head @ page = page, pwa = pwa, model=model}"></head>

<body class="${page.cssClassNames}" id="${page.id}" data-cmp-data-layer-enabled="${page.data ? true : false}"
  data-nopush="1" data-category="${properties.dataCategory}" data-page="${properties.dataPage}"
  data-index="${properties.dataIndex}" 
  data-acquisition-api-url="${model.acquisitionAPIURL}"
  data-pos-handler="
      {
           &quot;apiUrl&quot;: &quot;${model.currencyCookieAPIURL}&quot;,
           &quot;apiUrlManual&quot;: &quot;${model.currencyCookieManualAPIURl}&quot;,
           &quot;key&quot;: &quot;${model.key}&quot;,
           &quot;siteCode&quot;: &quot;${model.siteCode}&quot;,
           &quot;isoCountryCode&quot;: &quot;${model.ISOCountryCode}&quot;,
           &quot;languageCodeFromPage&quot;: &quot;${model.language}&quot;,
           &quot;pointOfSaleCodeFromPage&quot;: &quot;${model.POSFromPage}&quot;,
           &quot;apiUrlPosCurrencies&quot;: &quot;${model.PosCurrenciesURI}&quot;,
           &quot;apiUrlCurrencyManual&quot;: &quot;${model.CurrencyManualURI}&quot;,
           &quot;apiUrlPosCountries&quot;: &quot;${model.CountriesURI}&quot;

      }
      ">

  <sly data-sly-test="${properties.androidAppBanner}">
    <meta name="google-play-app" content="${properties.androidAppBannerID}">
  </sly>
  <sly data-sly-test="${properties.iosAppBanner}">
    <meta name="apple-itunes-app" content="app-id=${properties.iosAppBannerID}">
  </sly>
  <script data-sly-test.dataLayerEnabled="${page.data}">
    window.adobeDataLayer = window.adobeDataLayer || [];
    adobeDataLayer.push({
      page: JSON.parse("${page.data.json @ context='scriptString'}"),
      event: 'cmp:show',
      eventInfo: {
        path: 'page.${page.id @ context="scriptString"}'
      }
    });
  </script>
  <sly data-sly-test.isRedirectPage="${page.redirectTarget && (wcmmode.edit || wcmmode.preview)}"
    data-sly-call="${redirect.redirect @ redirectTarget = page.redirectTarget}"></sly>


  <sly data-sly-test="${!isRedirectPage}">
    <sly data-sly-include="body.skiptomaincontent.html"></sly>
    <sly data-sly-test="${!wcmmode.edit}" data-sly-include="one-trust.html"></sly>
    <sly data-sly-include="body.html"></sly>
    <sly data-sly-include="pos-handler.html" />
  </sly>
</body>

</html>

[Jörg_Hoh · Accepted solution]

data-sly-use.model="com.allb2bsites.core.models.PageHeadModel"

This code will try to instantiate the PageHeadModel interface, which does not work. 

 

data-sly-use.page="com.adobe.cq.wcm.core.components.models.Page" lang="${page.language.toLowerCase}"
data-sly-use.pwa="com.adobe.cq.wcm.core.components.models.PWA" data-sly-use.head="head.html"
data-sly-use.redirect="redirect.html" data-sly-use.hrefTemplate="href-langs.html"

models.Page and models.PWA are interfaces, but all methods have a default implementation, so I assume that the instantiation works for them (I am not a HTL expert).