RCP application cannot find ModelCleanupAddon class

问题

I have RCP application based on Luna release. After migrating to Luna 4.4.2 relase, I observe the following error

!ENTRY org.eclipse.e4.ui.workbench 4 0 2015-08-27 16:59:58.081
!MESSAGE Unable to load class 'org.eclipse.ui.internal.ide.application.addons.ModelCleanupAddon' from bundle '85'
!STACK 0
java.lang.ClassNotFoundException: org.eclipse.ui.internal.ide.application.addons.ModelCleanupAddon cannot be found by org.eclipse.ui.ide.application_1.0.501.v20141111-1238
    at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:432)
    at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:345)
    at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:337)
    at org.eclipse.osgi.internal.loader.ModuleClassLoader.loadClass(ModuleClassLoader.java:160)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at org.eclipse.osgi.internal.framework.EquinoxBundle.loadClass(EquinoxBundle.java:568)
    at org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.createFromBundle(ReflectionContributionFactory.java:102)
    at org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.doCreate(ReflectionContributionFactory.java:73)
    at org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.create(ReflectionContributionFactory.java:50)
    at org.eclipse.e4.ui.internal.workbench.swt.E4Application.createE4Workbench(E4Application.java:294)
    at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:601)
    at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
    at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:579)
    at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:150)
    at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:135)
    at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:134)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:380)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:235)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:648)
    at org.eclipse.equinox.launcher.Main.basicRun(Main.java:603)
    at org.eclipse.equinox.launcher.Main.run(Main.java:1465)
        at org.eclipse.equinox.launcher.Main.main(Main.java:1438) 

Root cause is 
    java.lang.ClassNotFoundException: org.eclipse.ui.internal.ide.application.addons.ModelCleanupAddon cannot be found by org.eclipse.ui.ide.application_

1.0.501.v20141111-1238.

What I schould intstall to Luna Release additionaly? Or may be I have configuration error? This issue is observed on 64 bits platform. RCP application is a DSL implementation based on xtext 2.8.4

Thank you in advance Alexander

回答1:

There is a similar bug report open in the Eclipse bugzilla: https://bugs.eclipse.org/bugs/show_bug.cgi?id=423923

Comments suggest that

your workspace is trying to load org.eclipse.e4.ui.workbench.addons.splitteraddon.SplitterAddon. This can happen if

1) you have o.e.ui.workbench from master in your workspace when launching from a 4.3.x target or

2) if you are opening an existing Luna workspace with 4.3.x

I had a similar exception when launching with a workspace that was created by an older version. In my case the workspace was created with 4.4 and the exception occured when launching a 4.5-based application on that workspace.

来源：https://stackoverflow.com/questions/32252658/rcp-application-cannot-find-modelcleanupaddon-class