java.util.ConcurrentModificationException: Caller uses obsolete token sequence which is no longer valid. Underlying token hierarchy has been modified: modCount=4 != upToDateModCount=8
Please report against caller's module which needs to be fixed (not the lexer module).
   at org.netbeans.api.lexer.TokenSequence.checkModCount(TokenSequence.java:748)
   at org.netbeans.api.lexer.TokenSequence.move(TokenSequence.java:632)
   at org.netbeans.modules.xml.schema.completion.CompletionResultItem.getInsertingText(CompletionResultItem.java:233)
   at org.netbeans.modules.xml.schema.completion.EndTagResultItem$1.run(EndTagResultItem.java:115)
   at org.netbeans.editor.GuardedDocument.runAtomic(GuardedDocument.java:314)
   at org.netbeans.modules.xml.schema.completion.EndTagResultItem.replaceText(EndTagResultItem.java:109)
   at org.netbeans.modules.xml.schema.completion.CompletionResultItem.defaultAction(CompletionResultItem.java:304)
   at org.netbeans.modules.editor.completion.CompletionImpl.dispatchKeyEvent(CompletionImpl.java:606)
   at org.netbeans.modules.editor.completion.CompletionImpl.keyPressed(CompletionImpl.java:378)
   at java.awt.AWTEventMulticaster.keyPressed(AWTEventMulticaster.java:233)
   at java.awt.Component.processKeyEvent(Component.java:6225)
   at javax.swing.JComponent.processKeyEvent(JComponent.java:2801)
   at java.awt.Component.processEvent(Component.java:6044)
   at java.awt.Container.processEvent(Container.java:2041)
   at java.awt.Component.dispatchEventImpl(Component.java:4630)
   at java.awt.Container.dispatchEventImpl(Container.java:2099)
   at java.awt.Component.dispatchEvent(Component.java:4460)
   at java.awt.KeyboardFocusManager.redispatchEvent(KeyboardFocusManager.java:1850)
   at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(DefaultKeyboardFocusManager.java:712)
   at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(DefaultKeyboardFocusManager.java:990)
   at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(DefaultKeyboardFocusManager.java:855)
   at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:676)
   at java.awt.Component.dispatchEventImpl(Component.java:4502)
   at java.awt.Container.dispatchEventImpl(Container.java:2099)
   at java.awt.Window.dispatchEventImpl(Window.java:2478)
   at java.awt.Component.dispatchEvent(Component.java:4460)
   at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
   at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:138)
   at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
   at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
   at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
   at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
   at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)