java.lang.AssertionError: Unknown sub type: 'error'
   at org.netbeans.modules.web.webkit.debugging.api.debugger.RemoteObject.getSubType(RemoteObject.java:142)
   at org.netbeans.modules.web.javascript.debugger.locals.VariablesModel.getProperties(VariablesModel.java:209)
   at org.netbeans.modules.web.javascript.debugger.locals.VariablesModel.getProperties(VariablesModel.java:198)
   at org.netbeans.modules.web.javascript.debugger.locals.VariablesModel.getChildrenCount(VariablesModel.java:267)
   at org.netbeans.modules.web.javascript.debugger.eval.ui.EvaluationResultsModel.getChildrenCount(EvaluationResultsModel.java:96)
   at org.netbeans.spi.viewmodel.Models$DelegatingTreeModel.getChildrenCount(Models.java:1829)
   at org.netbeans.spi.viewmodel.Models$CompoundModel.getChildrenCount(Models.java:4439)
   at org.netbeans.modules.viewmodel.TreeModelNode$TreeModelChildren.getModelChildren(TreeModelNode.java:1485)
   at org.netbeans.modules.viewmodel.TreeModelNode$TreeModelChildren.run(TreeModelNode.java:1446)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1443)
   at org.netbeans.modules.openide.util.GlobalLookup.execute(GlobalLookup.java:68)
   at org.openide.util.lookup.Lookups.executeWith(Lookups.java:303)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2058)