[FIXED] Problems occurred when invoking code from plug-in: "org.eclipse.core.resources"

Issue

How do I resolve the above reported error message? Additional details are given below:

Exception Stack Trace

java.lang.NullPointerException
    at org.eclipse.m2e.jdt.internal.MavenClasspathContainerInitializer.initialize(MavenClasspathContainerInitializer.java:48)
    at org.eclipse.jdt.internal.core.JavaModelManager.initializeContainer(JavaModelManager.java:2843)
    at org.eclipse.jdt.internal.core.JavaModelManager.getClasspathContainer(JavaModelManager.java:1878)
    at org.eclipse.jdt.core.JavaCore.getClasspathContainer(JavaCore.java:3128)
    at org.eclipse.jdt.internal.core.JavaProject.resolveClasspath(JavaProject.java:2691)
    at org.eclipse.jdt.internal.core.JavaProject.resolveClasspath(JavaProject.java:2855)
    at org.eclipse.jdt.internal.core.ClasspathChange.generateDelta(ClasspathChange.java:220)
    at org.eclipse.jdt.internal.core.DeltaProcessor.resourceChanged(DeltaProcessor.java:2052)
    at org.eclipse.jdt.internal.core.DeltaProcessingState.resourceChanged(DeltaProcessingState.java:470)
    at org.eclipse.core.internal.events.NotificationManager$1.run(NotificationManager.java:291)
    at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
    at org.eclipse.core.internal.events.NotificationManager.notify(NotificationManager.java:285)
    at org.eclipse.core.internal.events.NotificationManager.broadcastChanges(NotificationManager.java:149)
    at org.eclipse.core.internal.resources.Workspace.broadcastPostChange(Workspace.java:395)
    at org.eclipse.core.internal.resources.Workspace.endOperation(Workspace.java:1530)
    at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2353)
    at org.eclipse.wst.jsdt.internal.core.JavaModelManager.initializeAllContainers(JavaModelManager.java:2153)
    at org.eclipse.wst.jsdt.internal.core.JavaModelManager.getJsGlobalScopeContainer(JavaModelManager.java:1530)
    at org.eclipse.wst.jsdt.core.JavaScriptCore.getJsGlobalScopeContainer(JavaScriptCore.java:1319)
    at org.eclipse.wst.jsdt.internal.core.JavaProject.resolveClasspath(JavaProject.java:2740)
    at org.eclipse.wst.jsdt.internal.core.JavaProject.getResolvedClasspath(JavaProject.java:2019)
    at org.eclipse.wst.jsdt.core.JavaScriptCore.initializeAfterLoad(JavaScriptCore.java:2655)
    at org.eclipse.wst.jsdt.internal.ui.InitializeAfterLoadJob$RealJob.run(InitializeAfterLoadJob.java:32)
    at org.eclipse.core.internal.jobs.Worker.run(Worker.java:54)

Session Data

eclipse.buildId=I20120608-1400
java.version=1.7.0_08-ea
java.vendor=Oracle Corporation
BootLoader constants: OS=macosx, ARCH=x86_64, WS=cocoa, NL=en_US
Framework arguments:  -product org.eclipse.epp.package.jee.product -keyring /Users/ravisankars/.eclipse_keyring -showlocation
Command-line arguments:  -os macosx -ws cocoa -arch x86_64 -product org.eclipse.epp.package.jee.product -keyring /Users/ravisankars/.eclipse_keyring -showlocation

Solution

Quite a few things had happened since I first installed Eclipse, like (a) installing / uninstalling plugins (b) upgrading the IDE without correspondingly upgrading the workspace. Since the history has become complex, troubleshooting also got trick. Fresh installation along with importing the code base again, fixed the issue for me.

Answered By - Ken Russell
Answer Checked By - Marilyn (JavaFixing Volunteer)