com.instantiations.utils.reflect.ProjectClassLoader

[dfayerma]

I've go the following exception in the log when trying to read some of the
screens:

!ENTRY com.swtdesigner 4 4 2007-02-20 18:02:07.534
!MESSAGE Designer internal error [6.1.1.20070219212745]: com/instantiations/utils/reflect/ProjectClassLoader
!STACK 0
java.lang.NoClassDefFoundError: com/instantiations/utils/reflect/ProjectClassLoader
at com.swtdesigner.model.util.ast.ASTEditor.getProjectClassLoader(ASTEditor.java:274)
at com.swtdesigner.model.util.ast.ASTEditor.getProjectClassLoader(ASTEditor.java:270)
at com.swtdesigner.model.util.ast.ASTEditor.getWorkspaceClassLoader(ASTEditor.java:261)
at com.swtdesigner.model.converter.ExpressionConverter.getClassLoader(ExpressionConverter.java:1021)
at com.swtdesigner.model.converter.ExpressionConverter.getClassByName(ExpressionConverter.java:987)
at com.swtdesigner.model.converter.ExpressionConverter.convertQualifiedName(ExpressionConverter.java:463)
at com.swtdesigner.model.converter.ExpressionConverter.toValue(ExpressionConverter.java:103)
at com.swtdesigner.model.converter.IntegerConverter.toValue(IntegerConverter.java:189)
at com.swtdesigner.model.swt.layout.grid.GridDataInfo.fillStyleFromFourArgsCtor(GridDataInfo.java:290)
at com.swtdesigner.model.swt.layout.grid.GridDataInfo.fetchPropertiesValues(GridDataInfo.java:240)
at com.swtdesigner.model.swt.layout.grid.GridDataInfo.access$0(GridDataInfo.java:205)
at com.swtdesigner.model.swt.layout.grid.GridDataInfo$VSpanProperty.getSpanValue(GridDataInfo.java:1176)
at com.swtdesigner.model.swt.layout.grid.GridDataInfo$SpanProperty.getValue(GridDataInfo.java:1121)
at com.swtdesigner.actions.layout.AbstractAlignmentComposite$PropertyInfo.getValue(AbstractAlignmentComposite.java:151)
at com.swtdesigner.actions.layout.AbstractAlignmentComposite$IntegerPropertyInfo.showValue(AbstractAlignmentComposite.java:323)
at com.swtdesigner.actions.layout.AbstractAlignmentComposite.updateEditors(AbstractAlignmentComposite.java:73)
at com.swtdesigner.actions.layout.AbstractAlignmentComposite.updateEditors(AbstractAlignmentComposite.java:68)
at com.swtdesigner.model.swt.layout.grid.GridLayoutDataAlignmentControl.update(GridLayoutDataAlignmentControl.java:201)
at com.swtdesigner.model.swt.layout.grid.GridLayoutInfo.updateAlignment(GridLayoutInfo.java:1011)
at com.swtdesigner.model.swt.widgets.composite.AbstractCompositeInfo.updateAlignment(AbstractCompositeInfo.java:924)
at com.swtdesigner.actions.alignment.AlignmentWindow.update(AlignmentWindow.java:118)
at com.swtdesigner.actions.alignment.AlignmentWindowAction.update(AlignmentWindowAction.java:86)
at com.swtdesigner.actions.alignment.AlignmentWindowAction.run(AlignmentWindowAction.java:125)
at com.swtdesigner.gef.DesignerEditor$15.widgetSelected(DesignerEditor.java:908)
at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:90)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:66)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:928)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3348)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:2968)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:1914)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:1878)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:419)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at org.eclipse.ui.internal.ide.IDEApplication.run(IDEApplication.java:95)
at org.eclipse.core.internal.runtime.PlatformActivator$1.run(PlatformActivator.java:78)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:92)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:68)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:400)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:177)
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.core.launcher.Main.invokeFramework(Main.java:336)
at org.eclipse.core.launcher.Main.basicRun(Main.java:280)
at org.eclipse.core.launcher.Main.run(Main.java:977)
at org.eclipse.core.launcher.Main.main(Main.java:952)

[Eric Clayberg]

I've go the following exception in the log when trying to read some of the screens:
java.lang.NoClassDefFoundError: com/instantiations/utils/reflect/ProjectClassLoader

A NoClassDefFoundError exception is almost always an indication of an installation or configuration problem. I would recommend downloading and installing the product again.

Also see the following two FAQ entries.

What should I do if I encounter an NoSuchMethodError or NoClassDefFoundError using Designer?

What should I do if Designer does not work after installation?

[dfayerma]

Eric, you are right.
The problem was that I did not clear the <Eclipse>/configuration directory.

Once I cleared it, the problem went away.
Can you explane why this is needed?

Thanks.

[Eric Clayberg]

The problem was that I did not clear the <Eclipse>/configuration directory.
Once I cleared it, the problem went away.
Can you explane why this is needed?

Starting with Eclipse 3.0, Eclipse started to aggressively cache data from installed plugins (to decrease startup time).

The problem happens when the cache gets stale (which can often happen when you update a plugin from one version to another).

Starting eclipse up with the -clean option generally has the same effect as clearing the configuration directory.