Custom Error Pages Dispatcher AEM as Cloude Service PassThrough not working

Hi @sai_charanar,

AEM as a Cloud Service (AEMaaCS), where custom error handling works differently from traditional AMS setups due to the immutable nature of /apps and how error handling is sandboxed and virtualized differently.

In AEMaaCS:

1. Placing 404.jsp directly under /apps/acs-commons/... can cause interference with how ACS Commons features are resolved.

2. Dispatcher-based ErrorDocument rules do work, but they cause URL changes — which breaks your desired UX.

3. The x-aem-error-pass header only works with AEMaaCS’s built-in error handling logic and needs Cloud Manager/CDN awareness to behave as expected.

I would follow these approach (for AEMaaCS)

1. Use the AEMaaCS-supported ACS Commons error handler

ACS Commons does support AEMaaCS via /apps/acs-commons/components/utilities/errorpagehandler.

But don’t override or block access to /apps/acs-commons — instead:

Place your custom error pages under your own project path, e.g.:

/apps/your-project/components/errorpages/404.jsp

Then, in your error handler logic (default.jsp under /apps/sling/servlet/errorhandler/), call your custom page using a resource include or forward, like:

<%@ include file="/libs/foundation/global.jsp" %>
<%
    request.setAttribute("javax.servlet.error.status_code", 404);
    slingRequest.getRequestDispatcher("/apps/your-project/components/errorpages/404.jsp").forward(request, response);
%>

This keeps the URL intact.

2. Dispatcher Configuration:

Use a Dispatcher ErrorDocument directive but pair it with CDN headers to ensure AEM doesn't redirect to a new URL.

Example:

In your dispatcher.any or vhost.conf:

ErrorDocument 404 /content/your-site/en/error/404.html

Header set x-aem-error-pass "true" "expr=%{REQUEST_STATUS} == 404"

This tells the CDN and Dispatcher to forward the original request internally, not redirect.

Make sure:

• The 404 page is publishable and cached

• The path is available anonymously

• The CDN is configured to respect the x-aem-error-pass behavior (via Cloud Manager CDN config or Adobe support)

3. Avoid Overriding /apps/acs-commons

Do not place your project-specific 404 page inside /apps/acs-commons — even though it's tempting. It’s a shared utility area, and in AEMaaCS, it may cause package resolution issues or conflict with ACS Commons upgrades.

Recommended Structure:

/apps/your-project/components/errorpages/404.jsp
/apps/sling/servlet/errorhandler/default.jsp

default.jsp logic:

<%
    request.setAttribute("javax.servlet.error.status_code", 404);
    slingRequest.getRequestDispatcher("/apps/your-project/components/errorpages/404.jsp").forward(request, response);
%>

Hope that helps!

Regards,
Santosh