java.lang.IllegalStateException: This must happen in event thread!
        at org.netbeans.modules.refactoring.spi.impl.RefactoringPanel.checkEventThread(RefactoringPanel.java:127)
        at org.netbeans.modules.refactoring.spi.impl.ParametersPanel.showDialog(ParametersPanel.java:420)
        at org.netbeans.modules.refactoring.spi.impl.RefactoringPanel.refresh(RefactoringPanel.java:582)
        at org.netbeans.modules.refactoring.spi.impl.RefactoringPanel.<init>(RefactoringPanel.java:113)
        at org.netbeans.modules.refactoring.spi.ui.UI.openRefactoringUI(UI.java:59)
        at org.netbeans.modules.xml.refactoring.spi.SharedUtils.showDeleteRefactoringUI(SharedUtils.java:351)
        at org.netbeans.modules.xml.schema.abe.nodes.ABEAbstractNode.safeDelete(ABEAbstractNode.java:510)
        at org.netbeans.modules.xml.schema.abe.nodes.ABEAbstractNode.remove(ABEAbstractNode.java:316)
        at org.netbeans.modules.xml.schema.abe.nodes.ABEAbstractNode.destroy(ABEAbstractNode.java:353)
        at org.openide.explorer.ExplorerActionsImpl$DeleteActionPerformer.doDestroy(ExplorerActionsImpl.java:602)
        at org.openide.explorer.ExplorerActionsImpl$DeleteActionPerformer.actionPerformed(ExplorerActionsImpl.java:552)
        at org.openide.util.actions.CallbackSystemAction$DelegateAction$1.run(CallbackSystemAction.java:546)
        at org.netbeans.modules.openide.util.ActionsBridge$ActionRunnable.actionPerformed(ActionsBridge.java:89)
        at org.netbeans.core.ModuleActions.invokeAction(ModuleActions.java:82)
        at org.netbeans.modules.openide.actions.ActionsBridgeImpl.invokeAction(ActionsBridgeImpl.java:30)
        at org.netbeans.modules.openide.util.ActionsBridge$ActionRunnable.doRun(ActionsBridge.java:80)
        at org.netbeans.modules.openide.util.ActionsBridge$1.run(ActionsBridge.java:49)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:539)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:964)