java.lang.IllegalStateException: registerExternalRoots was already called before
        at org.netbeans.spi.project.support.ant.SourcesHelper.registerExternalRoots(SourcesHelper.java:513)
        at org.netbeans.modules.j2ee.earproject.EarSources$2.run(EarSources.java:93)
        at org.openide.util.Mutex.leaveImpl(Mutex.java:902)
        at org.openide.util.Mutex.leave(Mutex.java:835)
        at org.openide.util.Mutex.readAccess(Mutex.java:333)
        at org.openide.util.Mutex$1R.run(Mutex.java:1299)
        at org.netbeans.api.project.ProjectManager$2$1.run(ProjectManager.java:120)
        at org.openide.filesystems.EventControl.runAtomicAction(EventControl.java:120)
        at org.openide.filesystems.FileSystem.runAtomicAction(FileSystem.java:499)
        at org.openide.filesystems.FileUtil.runAtomicAction(FileUtil.java:167)
        at org.netbeans.api.project.ProjectManager$2.execute(ProjectManager.java:118)
        at org.openide.util.Mutex.doWrapperAccess(Mutex.java:1320)
        at org.openide.util.Mutex.readAccess(Mutex.java:275)
        at org.netbeans.modules.java.source.classpath.GlobalSourcePath.getLibsSources(GlobalSourcePath.java:518)
        at org.netbeans.modules.java.source.classpath.GlobalSourcePath.isLibrary(GlobalSourcePath.java:196)
        at org.netbeans.api.java.source.ClasspathInfo.<init>(ClasspathInfo.java:114)
        at org.netbeans.api.java.source.ClasspathInfo.create(ClasspathInfo.java:184)
        at org.netbeans.modules.j2ee.dd.impl.webservices.annotation.WebservicesMetadataModelImpl.<init>(WebservicesMetadataModelImpl.java:69)
        at org.netbeans.modules.j2ee.dd.spi.webservices.WebservicesMetadataModelFactory.createMetadataModel(WebservicesMetadataModelFactory.java:57)
        at org.netbeans.modules.web.project.ProjectWebModule.getWebservicesMetadataModel(ProjectWebModule.java:435)
        at org.netbeans.modules.web.project.jaxws.WebProjectJAXWSSupport.getWebservicesMetadataModel(WebProjectJAXWSSupport.java:579)
        at org.netbeans.modules.websvc.jaxws.api.JAXWSSupport.getWebservicesMetadataModel(JAXWSSupport.java:253)
        at org.netbeans.modules.websvc.core.jaxws.projects.JavaEEWSSupportLookupProvider$1.projectOpened(JavaEEWSSupportLookupProvider.java:90)
        at org.netbeans.spi.project.ui.ProjectOpenedHook$1.projectOpened(ProjectOpenedHook.java:81)
        at org.netbeans.spi.project.ui.support.UILookupMergerSupport$OpenHookImpl.projectOpened(UILookupMergerSupport.java:198)
        at org.netbeans.spi.project.ui.ProjectOpenedHook$1.projectOpened(ProjectOpenedHook.java:81)
        at org.netbeans.modules.project.ui.OpenProjectList.notifyOpened(OpenProjectList.java:911)
        at org.netbeans.modules.project.ui.OpenProjectList.doOpenProject(OpenProjectList.java:956)
        at org.netbeans.modules.project.ui.OpenProjectList.doOpen(OpenProjectList.java:567)
        at org.netbeans.modules.project.ui.OpenProjectList.access$1200(OpenProjectList.java:124)
        at org.netbeans.modules.project.ui.OpenProjectList$3.run(OpenProjectList.java:463)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:561)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:986)