Custom Eventlistener failed to activate

Following is error

Path : http://localhost:4502/system/console/components/4324

Error:

java.lang.NullPointerException at xxxxxx.core.listeners.SearchPageTagListener.activate(SearchPageTagListener.java:42) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:566) at org.apache.felix.scr.impl.inject.methods.BaseMethod.invokeMethod(BaseMethod.java:242) at org.apache.felix.scr.impl.inject.methods.BaseMethod.access$500(BaseMethod.java:41) at org.apache.felix.scr.impl.inject.methods.BaseMethod$Resolved.invoke(BaseMethod.java:678) at org.apache.felix.scr.impl.inject.methods.BaseMethod.invoke(BaseMethod.java:524) at org.apache.felix.scr.impl.inject.methods.ActivateMethod.invoke(ActivateMethod.java:318) at org.apache.felix.scr.impl.inject.methods.ActivateMethod.invoke(ActivateMethod.java:308) at org.apache.felix.scr.impl.manager.SingleComponentManager.createImplementationObject(SingleComponentManager.java:342) at org.apache.felix.scr.impl.manager.SingleComponentManager.createComponent(SingleComponentManager.java:115) at org.apache.felix.scr.impl.manager.SingleComponentManager.getService(SingleComponentManager.java:984) at org.apache.felix.scr.impl.manager.SingleComponentManager.getServiceInternal(SingleComponentManager.java:957) at org.apache.felix.scr.impl.manager.AbstractComponentManager.activateInternal(AbstractComponentManager.java:757) at org.apache.felix.scr.impl.manager.DependencyManager$SingleStaticCustomizer.addedService(DependencyManager.java:1091) at org.apache.felix.scr.impl.manager.DependencyManager$SingleStaticCustomizer.addedService(DependencyManager.java:1043) at org.apache.felix.scr.impl.manager.ServiceTracker$Tracked.customizerAdded(ServiceTracker.java:1216) at org.apache.felix.scr.impl.manager.ServiceTracker$Tracked.customizerAdded(ServiceTracker.java:1137) at org.apache.felix.scr.impl.manager.ServiceTracker$AbstractTracked.trackAdding(ServiceTracker.java:944) at org.apache.felix.scr.impl.manager.ServiceTracker$AbstractTracked.track(ServiceTracker.java:880) at org.apache.felix.scr.impl.manager.ServiceTracker$Tracked.serviceChanged(ServiceTracker.java:1168) at org.apache.felix.scr.impl.BundleComponentActivator$ListenerInfo.serviceChanged(BundleComponentActivator.java:125) at org.apache.felix.framework.EventDispatcher.invokeServiceListenerCallback(EventDispatcher.java:990) at org.apache.felix.framework.EventDispatcher.fireEventImmediately(EventDispatcher.java:838) at org.apache.felix.framework.EventDispatcher.fireServiceEvent(EventDispatcher.java:545) at org.apache.felix.framework.Felix.fireServiceEvent(Felix.java:4833) at org.apache.felix.framework.Felix.registerService(Felix.java:3804) at org.apache.felix.framework.BundleContextImpl.registerService(BundleContextImpl.java:328) at org.apache.felix.scr.impl.manager.AbstractComponentManager$3.register(AbstractComponentManager.java:907) at org.apache.felix.scr.impl.manager.AbstractComponentManager$3.register(AbstractComponentManager.java:893) at org.apache.felix.scr.impl.manager.RegistrationManager.changeRegistration(RegistrationManager.java:128) at org.apache.felix.scr.impl.manager.AbstractComponentManager.registerService(AbstractComponentManager.java:960) at org.apache.felix.scr.impl.manager.AbstractComponentManager.activateInternal(AbstractComponentManager.java:733) at org.apache.felix.scr.impl.manager.AbstractComponentManager.enableInternal(AbstractComponentManager.java:667) at org.apache.felix.scr.impl.manager.AbstractComponentManager.enable(AbstractComponentManager.java:433) at org.apache.felix.scr.impl.manager.ConfigurableComponentHolder.enableComponents(ConfigurableComponentHolder.java:666) at org.apache.felix.scr.impl.BundleComponentActivator.initialEnable(BundleComponentActivator.java:353) at org.apache.felix.scr.impl.Activator.loadComponents(Activator.java:553) at org.apache.felix.scr.impl.Activator.access$200(Activator.java:69) at org.apache.felix.scr.impl.Activator$ScrExtension.start(Activator.java:424) at org.apache.felix.scr.impl.AbstractExtender.createExtension(AbstractExtender.java:196) at org.apache.felix.scr.impl.AbstractExtender.modifiedBundle(AbstractExtender.java:169) at org.apache.felix.scr.impl.AbstractExtender.modifiedBundle(AbstractExtender.java:49) at org.osgi.util.tracker.BundleTracker$Tracked.customizerModified(BundleTracker.java:488) at org.osgi.util.tracker.BundleTracker$Tracked.customizerModified(BundleTracker.java:420) at org.osgi.util.tracker.AbstractTracked.track(AbstractTracked.java:232) at org.osgi.util.tracker.BundleTracker$Tracked.bundleChanged(BundleTracker.java:450) at org.apache.felix.framework.EventDispatcher.invokeBundleListenerCallback(EventDispatcher.java:915) at org.apache.felix.framework.EventDispatcher.fireEventImmediately(EventDispatcher.java:834) at org.apache.felix.framework.EventDispatcher.fireBundleEvent(EventDispatcher.java:516) at org.apache.felix.framework.Felix.fireBundleEvent(Felix.java:4817) at org.apache.felix.framework.Felix.startBundle(Felix.java:2336) at org.apache.felix.framework.BundleImpl.start(BundleImpl.java:998) at org.apache.felix.webconsole.internal.core.BaseUpdateInstallHelper.run(BaseUpdateInstallHelper.java:198) at java.base/java.lang.Thread.run(Thread.java:836)