As I was developing with STS and modifying a Spring bean file (actually a bean file created from a Spring Template project, i.e. mvc-config.xml), I got an Eclipse UI error about a "Widget Problem." This was when I had a task activited in Mylyn, and I may have had alt held down when double clicking within the Spring Explorer (even holding alt while right-click and open Java element).

Once this error occured, any other significant UI interact in Eclipse caused the widget problem. Eclipse returned to normal after de-activating the task.

here is the error from the Spring log:

Error Message:
Code:
Plug-in org.springframework.ide.eclipse.mylyn was unable to load class org.eclipse.mylyn.internal.context.ui.actions.InterestIncrementAction.
Stack Trace:

Code:
java.lang.ClassNotFoundException: org.eclipse.mylyn.internal.context.ui.actions.InterestIncrementAction
at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:494)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:410)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:398)
at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.loadClass(DefaultClassLoader.java:105)
at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
at org.eclipse.osgi.internal.loader.BundleLoader.loadClass(BundleLoader.java:326)
at org.eclipse.osgi.framework.internal.core.BundleHost.loadClass(BundleHost.java:231)
at org.eclipse.osgi.framework.internal.core.AbstractBundle.loadClass(AbstractBundle.java:1193)
at org.eclipse.core.internal.registry.osgi.RegistryStrategyOSGI.createExecutableExtension(RegistryStrategyOSGI.java:160)
at org.eclipse.core.internal.registry.ExtensionRegistry.createExecutableExtension(ExtensionRegistry.java:874)
at org.eclipse.core.internal.registry.ConfigurationElement.createExecutableExtension(ConfigurationElement.java:243)
at org.eclipse.core.internal.registry.ConfigurationElementHandle.createExecutableExtension(ConfigurationElementHandle.java:51)
at org.eclipse.ui.internal.WorkbenchPlugin.createExtension(WorkbenchPlugin.java:259)
at org.eclipse.ui.internal.PluginAction.createDelegate(PluginAction.java:122)
at org.eclipse.ui.internal.PluginAction.selectionChanged(PluginAction.java:275)
at org.eclipse.ui.internal.PluginAction.<init>(PluginAction.java:112)
at org.eclipse.ui.internal.ObjectPluginAction.<init>(ObjectPluginAction.java:83)
at org.eclipse.ui.internal.ActionDescriptor.createAction(ActionDescriptor.java:272)
at org.eclipse.ui.internal.ActionDescriptor.<init>(ActionDescriptor.java:176)
at org.eclipse.ui.internal.ActionDescriptor.<init>(ActionDescriptor.java:103)
at org.eclipse.ui.internal.ObjectActionContributor.createActionDescriptor(ObjectActionContributor.java:201)
at org.eclipse.ui.internal.PluginActionBuilder.readElement(PluginActionBuilder.java:161)
at org.eclipse.ui.internal.ObjectActionContributor.readElement(ObjectActionContributor.java:280)
at org.eclipse.ui.internal.registry.RegistryReader.readElements(RegistryReader.java:144)
at org.eclipse.ui.internal.registry.RegistryReader.readElementChildren(RegistryReader.java:133)
at org.eclipse.ui.internal.ObjectActionContributor.readConfigElement(ObjectActionContributor.java:251)
at org.eclipse.ui.internal.ObjectActionContributor.isApplicableTo(ObjectActionContributor.java:217)
at org.eclipse.ui.internal.ObjectContributorManager.isApplicableTo(ObjectContributorManager.java:303)
at org.eclipse.ui.internal.ObjectActionContributorManager.contributeObjectActions(ObjectActionContributorManager.java:83)
at org.eclipse.ui.internal.PopupMenuExtender.addObjectActions(PopupMenuExtender.java:262)
at org.eclipse.ui.internal.PopupMenuExtender.menuAboutToShow(PopupMenuExtender.java:339)
at org.eclipse.jface.action.MenuManager.fireAboutToShow(MenuManager.java:338)
at org.eclipse.jface.action.MenuManager.handleAboutToShow(MenuManager.java:469)
at org.eclipse.jface.action.MenuManager.access$1(MenuManager.java:465)
at org.eclipse.jface.action.MenuManager$2.menuShown(MenuManager.java:491)
at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:235)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1176)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1200)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1181)
at org.eclipse.swt.widgets.Menu._setVisible(Menu.java:199)
at org.eclipse.swt.widgets.Display.runPopups(Display.java:3519)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3109)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2405)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2369)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2221)
at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:500)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:493)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:113)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:194)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:368)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:559)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:514)
at org.eclipse.equinox.launcher.Main.run(Main.java:1311)
at org.eclipse.equinox.launcher.Main.main(Main.java:1287)
The error after this was:
Code:
Could not create action delegate for id: org.springframework.ide.eclipse.ui.interest.actions.InterestIncrementAction
I'm still on STS 2.3.0.