java.lang.IllegalArgumentException: URI is not hierarchical
        at java.io.File.<init>(File.java:363)
        at org.netbeans.modules.java.freeform.Classpaths$SourcePRI.computeMatcher(Classpaths.java:657)
        at org.netbeans.modules.java.freeform.Classpaths$SourcePRI.<init>(Classpaths.java:650)
        at org.netbeans.modules.java.freeform.Classpaths$MutableClassPathImplementation.initRoots(Classpaths.java:602)
        at org.netbeans.modules.java.freeform.Classpaths$MutableClassPathImplementation.change(Classpaths.java:623)
        at org.netbeans.modules.java.freeform.Classpaths.pathsChanged(Classpaths.java:531)
        at org.netbeans.modules.java.freeform.Classpaths.propertyChange(Classpaths.java:521)
        at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:339)
        at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:276)
        at org.netbeans.modules.ant.freeform.FreeformEvaluator.fireAnyChange(FreeformEvaluator.java:166)
        at org.netbeans.modules.ant.freeform.FreeformEvaluator.configurationXmlChanged(FreeformEvaluator.java:154)
        at org.netbeans.spi.project.support.ant.AntProjectHelper$5.run(AntProjectHelper.java:494)
        at org.netbeans.spi.project.support.ant.AntProjectHelper$5.run(AntProjectHelper.java:490)
        at org.openide.util.Mutex.readAccess(Mutex.java:327)
        at org.openide.util.Mutex$1R.run(Mutex.java:1299)
        at org.openide.util.Mutex.doWrapperAccess(Mutex.java:1318)
        at org.openide.util.Mutex.readAccess(Mutex.java:275)
        at org.netbeans.spi.project.support.ant.AntProjectHelper.fireChange(AntProjectHelper.java:489)
        at org.netbeans.spi.project.support.ant.AntProjectHelper.access$700(AntProjectHelper.java:99)
        at org.netbeans.spi.project.support.ant.AntProjectHelper$3.run(AntProjectHelper.java:452)
        at org.netbeans.spi.project.support.ant.AntProjectHelper$3.run(AntProjectHelper.java:451)
        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.spi.project.support.ant.AntProjectHelper$4.run(AntProjectHelper.java:466)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:572)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:997)