java.lang.NullPointerException
   at org.netbeans.modules.maven.execute.cmd.ExecutionEventObject$Tree.startFold(ExecutionEventObject.java:198)
   at org.netbeans.modules.maven.execute.CommandLineOutputHandler$Output.run(CommandLineOutputHandler.java:373)
   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)