java.lang.IllegalArgumentException: Already listening to C:\WORK\dashboard\webapps\performancedashboard\AllInOnePerformanceDashboard\src\java
        at org.openide.filesystems.FileUtil.addFileChangeListener(FileUtil.java:242)
        at org.netbeans.modules.java.api.common.SourceRoots$ProjectMetadataListener.add(SourceRoots.java:511)
        at org.netbeans.modules.java.api.common.SourceRoots$4.run(SourceRoots.java:257)
        at org.netbeans.modules.java.api.common.SourceRoots$4.run(SourceRoots.java:235)
        at org.openide.util.Mutex.readAccess(Mutex.java:285)
        at org.netbeans.modules.java.api.common.SourceRoots.getRootURLs(SourceRoots.java:235)
        at org.netbeans.modules.java.api.common.SourceRoots$3.run(SourceRoots.java:210)
        at org.netbeans.modules.java.api.common.SourceRoots$3.run(SourceRoots.java:205)
        at org.openide.util.Mutex.readAccess(Mutex.java:285)
        at org.netbeans.modules.java.api.common.SourceRoots.getRoots(SourceRoots.java:205)
        at org.netbeans.modules.java.api.common.classpath.ClassPathProviderImpl.getPrimarySrcPath(ClassPathProviderImpl.java:138)
        at org.netbeans.modules.java.api.common.classpath.ClassPathProviderImpl.getType(ClassPathProviderImpl.java:174)
        at org.netbeans.modules.java.api.common.classpath.ClassPathProviderImpl.getSourcepath(ClassPathProviderImpl.java:277)
        at org.netbeans.modules.java.api.common.classpath.ClassPathProviderImpl.findClassPath(ClassPathProviderImpl.java:315)
        at org.netbeans.modules.web.project.classpath.ClassPathProviderImpl.findClassPath(ClassPathProviderImpl.java:241)
        at org.netbeans.spi.java.project.support.ClassPathProviderMerger$ProxyClassPathImplementation.checkProviders(ClassPathProviderMerger.java:165)
        at org.netbeans.spi.java.project.support.ClassPathProviderMerger$ProxyClassPathImplementation.<init>(ClassPathProviderMerger.java:148)
        at org.netbeans.spi.java.project.support.ClassPathProviderMerger$CPProvider.findClassPath(ClassPathProviderMerger.java:105)
        at org.netbeans.modules.java.project.ProjectClassPathProvider.findClassPath(ProjectClassPathProvider.java:65)
        at org.netbeans.api.java.classpath.ClassPath.getClassPath(ClassPath.java:550)
        at org.netbeans.modules.java.source.usages.BuildArtifactMapperImpl$FileBuildQueryImpl.getStatus(BuildArtifactMapperImpl.java:547)
        at org.netbeans.api.queries.FileBuiltQuery.getStatus(FileBuiltQuery.java:99)
        at org.netbeans.modules.java.JavaNode$BuildStatusTask.run(JavaNode.java:326)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:577)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1030)