java.lang.AssertionError: Null children for accurate span
   at org.netbeans.modules.editor.lib2.view.ViewBuilder.replaceRepaintViews(ViewBuilder.java:1242)
   at org.netbeans.modules.editor.lib2.view.ViewBuilder.createReplaceRepaintViews(ViewBuilder.java:687)
   at org.netbeans.modules.editor.lib2.view.ViewUpdates.updateViewsByModification(ViewUpdates.java:311)
   at org.netbeans.modules.editor.lib2.view.ViewUpdates.insertUpdate(ViewUpdates.java:247)
   at sun.reflect.GeneratedMethodAccessor53.invoke(GeneratedMethodAccessor53.java:0)
   at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
   at java.lang.reflect.Method.invoke(Method.java:601)
   at org.openide.util.WeakListenerImpl$ProxyListener.invoke(WeakListenerImpl.java:457)
   at $Proxy22.insertUpdate(.java:0)
   at org.netbeans.lib.editor.util.swing.PriorityDocumentListenerList.insertUpdate(PriorityDocumentListenerList.java:85)
   at javax.swing.text.AbstractDocument.fireInsertUpdate(AbstractDocument.java:202)
   at org.netbeans.editor.BaseDocument.fireInsertUpdate(BaseDocument.java:1563)
   at org.netbeans.editor.BaseDocument.handleInsertString(BaseDocument.java:808)
   at org.netbeans.editor.BaseDocument$FilterBypassImpl.insertString(BaseDocument.java:2421)
   at javax.swing.text.DocumentFilter.insertString(DocumentFilter.java:100)
   at org.openide.text.CloneableEditorSupport$DocFilter.insertString(CloneableEditorSupport.java:3048)
   at org.netbeans.editor.BaseDocument.insertString(BaseDocument.java:746)
   at org.netbeans.modules.html.palette.HTMLPaletteUtilities.insert(HTMLPaletteUtilities.java:199)
   at org.netbeans.modules.html.palette.HtmlPaletteUtilities.access$000(HtmlPaletteUtilities.java:69)
   at org.netbeans.modules.html.palette.HtmlPaletteUtilities$1.run(HtmlPaletteUtilities.java:167)
   at org.netbeans.editor.GuardedDocument.runAtomic(GuardedDocument.java:317)
   at org.netbeans.modules.html.palette.HTMLPaletteUtilities.insert(HTMLPaletteUtilities.java:162)
   at org.netbeans.modules.html.palette.HTMLPaletteUtilities.insert(HTMLPaletteUtilities.java:148)
   at org.netbeans.modules.html.palette.items.TABLE.handleTransfer(TABLE.java:82)
   at org.openide.text.QuietEditorPane$DelegatingTransferHandler.importData(QuietEditorPane.java:360)
   at javax.swing.TransferHandler.importData(TransferHandler.java:826)
   at javax.swing.TransferHandler$DropHandler.drop(TransferHandler.java:1536)
   at java.awt.dnd.DropTarget.drop(DropTarget.java:450)
   at javax.swing.TransferHandler$SwingDropTarget.drop(TransferHandler.java:1274)
   at org.openide.text.QuietEditorPane$DelegatingDropTarget.drop(QuietEditorPane.java:509)
   at sun.awt.dnd.SunDropTargetContextPeer.processDropMessage(SunDropTargetContextPeer.java:537)
   at sun.awt.X11.XDropTargetContextPeer.processDropMessage(XDropTargetContextPeer.java:184)
   at sun.awt.dnd.SunDropTargetContextPeer$EventDispatcher.dispatchDropEvent(SunDropTargetContextPeer.java:851)
   at sun.awt.dnd.SunDropTargetContextPeer$EventDispatcher.dispatchEvent(SunDropTargetContextPeer.java:775)
   at sun.awt.dnd.SunDropTargetEvent.dispatch(SunDropTargetEvent.java:48)
   at java.awt.Component.dispatchEventImpl(Component.java:4716)
   at java.awt.Container.dispatchEventImpl(Container.java:2287)
   at java.awt.Component.dispatchEvent(Component.java:4687)
   at java.awt.LightweightDispatcher.retargetMouseEvent(LightweightDispatcher.java:4832)
   at java.awt.LightweightDispatcher.processDropTargetEvent(LightweightDispatcher.java:4566)
   at java.awt.LightweightDispatcher.dispatchEvent(LightweightDispatcher.java:4417)
   at java.awt.Container.dispatchEventImpl(Container.java:2273)
   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)