java.lang.AssertionError: Null textComponent
   at org.netbeans.modules.editor.lib2.view.ViewBuilder.repaintAndReplaceViews(ViewBuilder.java:361)
   at org.netbeans.modules.editor.lib2.view.ViewUpdates.reinitViews(ViewUpdates.java:133)
   at org.netbeans.modules.editor.lib2.view.DocumentView.reinitViews(DocumentView.java:360)
   at org.netbeans.modules.editor.lib2.view.DocumentView$3.preferenceChange(DocumentView.java:480)
Caused: java.lang.reflect.InvocationTargetException
   at sun.reflect.GeneratedMethodAccessor67.invoke(GeneratedMethodAccessor67.java:0)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
   at java.lang.reflect.Method.invoke(Method.java:597)
   at org.openide.util.WeakListenerImpl$ProxyListener.invoke(WeakListenerImpl.java:451)
Caused: java.lang.reflect.UndeclaredThrowableException
   at $Proxy11.preferenceChange(.java:0)
   at java.util.prefs.AbstractPreferences$EventDispatchThread.run(AbstractPreferences.java:1475)