I've just installed the Bzr4IntelliJ VCS integration plugin, and I get the following exception:
Implementing class [Plugin: bzr4intellij]
com.intellij.diagnostic.PluginException: Implementing class [Plugin: bzr4intellij]
at com.intellij.ide.plugins.cl.PluginClassLoader.a(PluginClassLoader.java:127)
at com.intellij.ide.plugins.cl.PluginClassLoader.a(PluginClassLoader.java:77)
at com.intellij.ide.plugins.cl.PluginClassLoader.loadClass(PluginClassLoader.java:66)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
at org.emergent.bzr4j.intellij.BzrVcs.<init>(BzrVcs.java:161)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
at org.picocontainer.defaults.InstantiatingComponentAdapter.newInstance(InstantiatingComponentAdapter.java:193)
at org.picocontainer.defaults.ConstructorInjectionComponentAdapter$1.run(ConstructorInjectionComponentAdapter.java:220)
at org.picocontainer.defaults.ThreadLocalCyclicDependencyGuard.observe(ThreadLocalCyclicDependencyGuard.java:53)
at org.picocontainer.defaults.ConstructorInjectionComponentAdapter.getComponentInstance(ConstructorInjectionComponentAdapter.java:248)
at com.intellij.util.pico.ConstructorInjectionComponentAdapter.getComponentInstance(ConstructorInjectionComponentAdapter.java:59)
at com.intellij.openapi.extensions.AbstractExtensionPointBean.instantiate(AbstractExtensionPointBean.java:75)
at com.intellij.openapi.extensions.AbstractExtensionPointBean.instantiate(AbstractExtensionPointBean.java:68)
at com.intellij.openapi.extensions.AbstractExtensionPointBean.instantiate(AbstractExtensionPointBean.java:63)
at com.intellij.openapi.vcs.impl.VcsEP.a(VcsEP.java:81)
at com.intellij.openapi.vcs.impl.VcsEP.getVcs(VcsEP.java:61)
at com.intellij.openapi.vcs.impl.projectlevelman.AllVcses.getByName(AllVcses.java:103)
at com.intellij.openapi.vcs.impl.ProjectLevelVcsManagerImpl.findVcsByName(ProjectLevelVcsManagerImpl.java:179)
at com.intellij.openapi.vcs.configurable.VcsManagerConfigurable$1.compute(VcsManagerConfigurable.java:160)
at com.intellij.openapi.vcs.configurable.VcsManagerConfigurable$1.compute(VcsManagerConfigurable.java:156)
at com.intellij.openapi.util.NotNullLazyValue.getValue(NotNullLazyValue.java:39)
at com.intellij.openapi.vcs.configurable.VcsManagerConfigurable$2.disposeUIResources(VcsManagerConfigurable.java:198)
at com.intellij.openapi.options.ex.ConfigurableCardPanel.dispose(ConfigurableCardPanel.java:109)
at com.intellij.openapi.options.ex.ConfigurableCardPanel.dispose(ConfigurableCardPanel.java:35)
at com.intellij.ui.CardLayoutPanel.removeAll(CardLayoutPanel.java:197)
at com.intellij.ui.CardLayoutPanel.dispose(CardLayoutPanel.java:68)
at com.intellij.openapi.util.Disposer$1.execute(Disposer.java:46)
at com.intellij.openapi.util.Disposer$1.execute(Disposer.java:43)
at com.intellij.openapi.util.objectTree.ObjectNode$1.execute(ObjectNode.java:132)
at com.intellij.openapi.util.objectTree.ObjectNode$1.execute(ObjectNode.java:106)
at com.intellij.openapi.util.objectTree.ObjectTree.executeActionWithRecursiveGuard(ObjectTree.java:146)
at com.intellij.openapi.util.objectTree.ObjectNode.execute(ObjectNode.java:106)
at com.intellij.openapi.util.objectTree.ObjectNode$1.execute(ObjectNode.java:122)
at com.intellij.openapi.util.objectTree.ObjectNode$1.execute(ObjectNode.java:106)
at com.intellij.openapi.util.objectTree.ObjectTree.executeActionWithRecursiveGuard(ObjectTree.java:146)
at com.intellij.openapi.util.objectTree.ObjectNode.execute(ObjectNode.java:106)
at com.intellij.openapi.util.objectTree.ObjectNode$1.execute(ObjectNode.java:122)
at com.intellij.openapi.util.objectTree.ObjectNode$1.execute(ObjectNode.java:106)
at com.intellij.openapi.util.objectTree.ObjectTree.executeActionWithRecursiveGuard(ObjectTree.java:146)
at com.intellij.openapi.util.objectTree.ObjectNode.execute(ObjectNode.java:106)
at com.intellij.openapi.util.objectTree.ObjectNode$1.execute(ObjectNode.java:122)
at com.intellij.openapi.util.objectTree.ObjectNode$1.execute(ObjectNode.java:106)
at com.intellij.openapi.util.objectTree.ObjectTree.executeActionWithRecursiveGuard(ObjectTree.java:146)
at com.intellij.openapi.util.objectTree.ObjectNode.execute(ObjectNode.java:106)
at com.intellij.openapi.util.objectTree.ObjectTree.executeAll(ObjectTree.java:132)
at com.intellij.openapi.util.Disposer.dispose(Disposer.java:107)
at com.intellij.openapi.util.Disposer.dispose(Disposer.java:103)
at com.intellij.openapi.ui.DialogWrapper.close(DialogWrapper.java:426)
at com.intellij.openapi.ui.DialogWrapper.close(DialogWrapper.java:430)
at com.intellij.openapi.ui.DialogWrapper.doCancelAction(DialogWrapper.java:927)
at com.intellij.openapi.ui.DialogWrapper.doCancelAction(DialogWrapper.java:947)
at com.intellij.openapi.options.newEditor.SettingsDialog.doCancelAction(SettingsDialog.java:163)
at com.intellij.openapi.ui.DialogWrapper$18.actionPerformed(DialogWrapper.java:1714)
at javax.swing.JComponent$ActionStandin.actionPerformed(JComponent.java:3413)
at javax.swing.SwingUtilities.notifyAction(SwingUtilities.java:1662)
at javax.swing.JComponent.processKeyBinding(JComponent.java:2870)
at javax.swing.KeyboardManager.fireBinding(KeyboardManager.java:307)
at javax.swing.KeyboardManager.fireKeyboardAction(KeyboardManager.java:250)
at javax.swing.JComponent.processKeyBindingsForAllComponents(JComponent.java:2962)
at javax.swing.JComponent.processKeyBindings(JComponent.java:2954)
at javax.swing.JComponent.processKeyEvent(JComponent.java:2833)
at java.awt.Component.processEvent(Component.java:6293)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4872)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4698)
at java.awt.KeyboardFocusManager.redispatchEvent(KeyboardFocusManager.java:1887)
at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(DefaultKeyboardFocusManager.java:762)
at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(DefaultKeyboardFocusManager.java:1027)
at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(DefaultKeyboardFocusManager.java:899)
at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:727)
at java.awt.Component.dispatchEventImpl(Component.java:4742)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Window.dispatchEventImpl(Window.java:2719)
at java.awt.Component.dispatchEvent(Component.java:4698)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:747)
at java.awt.EventQueue.access$300(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:706)
at java.awt.EventQueue$3.run(EventQueue.java:704)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:77)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue$4.run(EventQueue.java:720)
at java.awt.EventQueue$4.run(EventQueue.java:718)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:77)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:717)
at com.intellij.ide.IdeEventQueue.f(IdeEventQueue.java:866)
at com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.java:623)
at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.java:381)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:154)
at java.awt.WaitDispatchSupport$2.run(WaitDispatchSupport.java:182)
at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:221)
at java.security.AccessController.doPrivileged(Native Method)
at java.awt.WaitDispatchSupport.enter(WaitDispatchSupport.java:219)
at java.awt.Dialog.show(Dialog.java:1082)
at com.intellij.openapi.ui.impl.DialogWrapperPeerImpl$MyDialog.show(DialogWrapperPeerImpl.java:792)
at com.intellij.openapi.ui.impl.DialogWrapperPeerImpl.show(DialogWrapperPeerImpl.java:465)
at com.intellij.openapi.ui.DialogWrapper.invokeShow(DialogWrapper.java:1638)
at com.intellij.openapi.ui.DialogWrapper.show(DialogWrapper.java:1587)
at com.intellij.ide.actions.ShowSettingsUtilImpl.showSettingsDialog(ShowSettingsUtilImpl.java:118)
at com.intellij.ide.actions.ShowSettingsAction.actionPerformed(ShowSettingsAction.java:65)
at com.intellij.openapi.actionSystem.ex.ActionUtil.performActionDumbAware(ActionUtil.java:182)
at com.intellij.openapi.actionSystem.impl.ActionButton.a(ActionButton.java:161)
at com.intellij.openapi.actionSystem.impl.ActionButton.a(ActionButton.java:125)
at com.intellij.openapi.actionSystem.impl.ActionButton.processMouseEvent(ActionButton.java:299)
at java.awt.Component.processEvent(Component.java:6281)
at java.awt.Container.processEvent(Container.java:2229)
at java.awt.Component.dispatchEventImpl(Component.java:4872)
at java.awt.Container.dispatchEventImpl(Container.java:2287)
at java.awt.Component.dispatchEvent(Component.java:4698)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
at java.awt.Container.dispatchEventImpl(Container.java:2273)
at java.awt.Window.dispatchEventImpl(Window.java:2719)
at java.awt.Component.dispatchEvent(Component.java:4698)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:747)
at java.awt.EventQueue.access$300(EventQueue.java:103)
at java.awt.EventQueue$3.run(EventQueue.java:706)
at java.awt.EventQueue$3.run(EventQueue.java:704)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:77)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:87)
at java.awt.EventQueue$4.run(EventQueue.java:720)
at java.awt.EventQueue$4.run(EventQueue.java:718)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:77)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:717)
at com.intellij.ide.IdeEventQueue.f(IdeEventQueue.java:866)
at com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.java:650)
at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.java:381)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:150)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:146)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:138)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:91)
Caused by: java.lang.IncompatibleClassChangeError: Implementing class
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:800)
at java.lang.ClassLoader.defineClass(ClassLoader.java:643)
at com.intellij.util.lang.UrlClassLoader._defineClass(UrlClassLoader.java:257)
at com.intellij.util.lang.UrlClassLoader.defineClass(UrlClassLoader.java:253)
at com.intellij.util.lang.UrlClassLoader._findClass(UrlClassLoader.java:222)
at com.intellij.ide.plugins.cl.PluginClassLoader.a(PluginClassLoader.java:124)
... 142 more
This exception occurs in several places. Most easily it is reproducible by going to File > Settings... > Version Control > Bazaar
Then the exception occurs and the spinner continues to turn in the settings dialog.