java.lang.IllegalStateException: Too many transactions; only one at a time is allowed!
   at org.netbeans.modules.editor.lib2.typinghooks.DeletedTextInterceptorsManager.openTransaction(DeletedTextInterceptorsManager.java:96)
   at org.netbeans.editor.BaseKit$DeleteCharAction.actionPerformed(BaseKit.java:1858)
   at org.netbeans.editor.BaseAction.actionPerformed(BaseAction.java:339)
   at org.openide.util.actions.ActionInvoker$1.run(ActionInvoker.java:93)
   at org.openide.util.actions.ActionInvoker$ActionRunnable.actionPerformed(ActionInvoker.java:162)
   at org.netbeans.core.ModuleActions.invokeAction(ModuleActions.java:109)
   at org.netbeans.modules.openide.actions.ActionsBridgeImpl.invokeAction(ActionsBridgeImpl.java:60)
   at org.openide.util.actions.ActionInvoker$ActionRunnable.doRun(ActionInvoker.java:153)
   at org.openide.util.actions.ActionInvoker$2.run(ActionInvoker.java:110)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1454)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2036)
Caused: org.openide.util.RequestProcessor$SlowItem: task failed due to: java.lang.IllegalStateException: Too many transactions; only one at a time is allowed!
   at org.openide.util.RequestProcessor.post(RequestProcessor.java:424)
   at org.openide.util.actions.ActionInvoker.doPerformAction(ActionInvoker.java:114)
   at org.openide.util.actions.ActionInvoker.invokeAction(ActionInvoker.java:99)
   at org.openide.awt.GeneralAction$BaseDelAction.actionPerformed(GeneralAction.java:234)
   at org.openide.windows.TopComponent.processKeyBinding(TopComponent.java:1176)
   at javax.swing.JComponent.processKeyBindings(JComponent.java:2940)
   at javax.swing.JComponent.processKeyEvent(JComponent.java:2842)
   at org.openide.explorer.view.TreeView$ExplorerTree.processKeyEvent(TreeView.java:1911)
   at java.awt.Component.processEvent(Component.java:6282)
   at java.awt.Container.processEvent(Container.java:2229)
   at java.awt.Component.dispatchEventImpl(Component.java:4861)
   at java.awt.Container.dispatchEventImpl(Container.java:2287)
   at java.awt.Component.dispatchEvent(Component.java:4687)
   at java.awt.KeyboardFocusManager.redispatchEvent(KeyboardFocusManager.java:1895)
   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:4731)
   at java.awt.Container.dispatchEventImpl(Container.java:2287)
   at java.awt.Window.dispatchEventImpl(Window.java:2719)
   at java.awt.Component.dispatchEvent(Component.java:4687)
   at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:723)
   at java.awt.EventQueue.access$200(EventQueue.java:103)
   at java.awt.EventQueue$3.run(EventQueue.java:682)
   at java.awt.EventQueue$3.run(EventQueue.java:680)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
   at java.awt.EventQueue$4.run(EventQueue.java:696)
   at java.awt.EventQueue$4.run(EventQueue.java:694)
   at java.security.AccessController.doPrivileged(AccessController.java:0)
   at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:693)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:158)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:244)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:163)
   at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:147)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:139)
   at java.awt.EventDispatchThread.run(EventDispatchThread.java:97)