java.lang.IllegalArgumentException: URI is not hierarchical
        at java.io.File.<init>(File.java:363)
        at org.netbeans.modules.java.freeform.Classpaths$SourcePRI.computeMatcher(Classpaths.java:655)
        at org.netbeans.modules.java.freeform.Classpaths$SourcePRI.<init>(Classpaths.java:648)
        at org.netbeans.modules.java.freeform.Classpaths$MutableClassPathImplementation.initRoots(Classpaths.java:600)
        at org.netbeans.modules.java.freeform.Classpaths$MutableClassPathImplementation.change(Classpaths.java:621)
        at org.netbeans.modules.java.freeform.Classpaths.pathsChanged(Classpaths.java:529)
        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$3.run(AntProjectHelper.java:492)
        at org.netbeans.spi.project.support.ant.AntProjectHelper$3.run(AntProjectHelper.java:488)
        at org.openide.util.Mutex.readAccess(Mutex.java:285)
        at org.netbeans.spi.project.support.ant.AntProjectHelper.fireChange(AntProjectHelper.java:487)
        at org.netbeans.spi.project.support.ant.AntProjectHelper.access$1300(AntProjectHelper.java:100)
        at org.netbeans.spi.project.support.ant.AntProjectHelper$ActionImpl.run(AntProjectHelper.java:1273)
        at org.netbeans.spi.project.support.ant.AntProjectHelper$ActionImpl.run(AntProjectHelper.java:1262)
        at org.openide.util.Mutex.readAccess(Mutex.java:285)
        at org.netbeans.spi.project.support.ant.AntProjectHelper$RunnableImpl.run(AntProjectHelper.java:1258)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:572)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:997)