java.lang.NullPointerException: The fo parameter cannot be null
   at org.openide.util.Parameters.notNull(Parameters.java:89)
   at org.netbeans.modules.j2ee.dd.api.web.DDProvider.getDDRoot(DDProvider.java:114)
   at org.netbeans.modules.j2ee.dd.api.web.DDProvider.getDDRootCopy(DDProvider.java:216)
   at org.netbeans.modules.web.wicket.framework.WicketFrameworkProvider$CreateWicketFiles.run(WicketFrameworkProvider.java:403)
   at org.openide.filesystems.EventControl.runAtomicAction(EventControl.java:125)
   at org.openide.filesystems.FileSystem.runAtomicAction(FileSystem.java:566)
   at org.netbeans.modules.web.wicket.framework.WicketFrameworkProvider.extendImpl(WicketFrameworkProvider.java:105)
   at org.netbeans.modules.web.wicket.framework.WicketWebModuleExtender.extend(WicketWebModuleExtender.java:359)
   at org.netbeans.modules.maven.webframeworks.WebFrameworksPanel.applyChanges(WebFrameworksPanel.java:131)
   at org.netbeans.modules.maven.webframeworks.WebFrameworksPanelProvider$1$1.run(WebFrameworksPanelProvider.java:86)
Caused: org.openide.util.RequestProcessor$SlowItem: task failed due to: java.lang.NullPointerException: The fo parameter cannot be null
   at org.openide.util.RequestProcessor.post(RequestProcessor.java:425)
   at org.netbeans.modules.maven.webframeworks.WebFrameworksPanelProvider$1.actionPerformed(WebFrameworksPanelProvider.java:84)
   at org.netbeans.modules.project.uiapi.CustomizerDialog$OptionListener.storePerformed(CustomizerDialog.java:335)
   at org.netbeans.modules.project.uiapi.CustomizerDialog$OptionListener.access$400(CustomizerDialog.java:239)
   at org.netbeans.modules.project.uiapi.CustomizerDialog$OptionListener$2$1.run(CustomizerDialog.java:297)
   at org.openide.util.Mutex.writeAccess(Mutex.java:397)
   at org.netbeans.modules.project.uiapi.CustomizerDialog$OptionListener$2.run(CustomizerDialog.java:291)
   at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1424)
   at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1968)