java.lang.NullPointerException
   at org.netbeans.core.NbURLDisplayer$NbBrowser.access$500(NbURLDisplayer.java:136)
   at org.netbeans.core.NbURLDisplayer.warmBrowserUp(NbURLDisplayer.java:120)
   at org.netbeans.core.NbURLDisplayer.access$000(NbURLDisplayer.java:72)
   at org.netbeans.core.NbURLDisplayer$1.run(NbURLDisplayer.java:84)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1454)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2036)
Caused: org.openide.util.RequestProcessor$SlowItem: task failed due to: java.lang.NullPointerException
   at org.openide.util.RequestProcessor.post(RequestProcessor.java:424)
   at org.netbeans.core.NbURLDisplayer.showURL(NbURLDisplayer.java:80)
   at org.netbeans.modules.maven.j2ee.ExecutionChecker.performDeploy(ExecutionChecker.java:188)
   at org.netbeans.modules.maven.j2ee.ExecutionChecker.executionResult(ExecutionChecker.java:130)
   at org.netbeans.modules.maven.execute.MavenCommandLineExecutor.run(MavenCommandLineExecutor.java:212)
   at org.netbeans.core.execution.RunClassThread.run(RunClassThread.java:153)