java.lang.IllegalArgumentException: URI is not hierarchical
        at java.io.File.<init>(File.java:363)
        at org.netbeans.modules.java.freeform.Classpaths$SourcePRI.computeMatcher(Classpaths.java:653)
        at org.netbeans.modules.java.freeform.Classpaths$SourcePRI.<init>(Classpaths.java:646)
        at org.netbeans.modules.java.freeform.Classpaths$MutableClassPathImplementation.initRoots(Classpaths.java:598)
        at org.netbeans.modules.java.freeform.Classpaths$MutableClassPathImplementation.<init>(Classpaths.java:548)
        at org.netbeans.modules.java.freeform.Classpaths.getPath(Classpaths.java:387)
        at org.netbeans.modules.java.freeform.Classpaths.openedImpl(Classpaths.java:281)
        at org.netbeans.modules.java.freeform.Classpaths.access$100(Classpaths.java:114)
        at org.netbeans.modules.java.freeform.Classpaths$2.run(Classpaths.java:235)
        at org.netbeans.modules.java.freeform.Classpaths$2.run(Classpaths.java:234)
        at org.openide.util.Mutex.readAccess(Mutex.java:327)
        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:215)
        at org.netbeans.api.project.ProjectManager$2.execute(ProjectManager.java:118)
        at org.openide.util.Mutex.doWrapperAccess(Mutex.java:1320)
        at org.openide.util.Mutex.readAccess(Mutex.java:275)
        at org.netbeans.modules.java.freeform.Classpaths.opened(Classpaths.java:233)
        at org.netbeans.modules.java.freeform.LookupProviderImpl$OpenHook.projectOpened(LookupProviderImpl.java:123)
        at org.netbeans.spi.project.ui.ProjectOpenedHook$1.projectOpened(ProjectOpenedHook.java:81)
        at org.netbeans.modules.project.ui.OpenProjectList.notifyOpened(OpenProjectList.java:951)
        at org.netbeans.modules.project.ui.OpenProjectList.doOpenProject(OpenProjectList.java:999)
        at org.netbeans.modules.project.ui.OpenProjectList.doOpen(OpenProjectList.java:598)
        at org.netbeans.modules.project.ui.OpenProjectList.access$1100(OpenProjectList.java:123)
        at org.netbeans.modules.project.ui.OpenProjectList$3.run(OpenProjectList.java:494)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:561)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:986)