java.lang.NullPointerException
        at org.netbeans.spi.project.support.ant.PathMatcher.matches(PathMatcher.java:183)
        at org.netbeans.modules.ant.freeform.ui.FolderNodeFactory$GroupDataFilter.acceptFileObject(FolderNodeFactory.java:281)
        at org.openide.loaders.FolderChildren$1R.run(FolderChildren.java:157)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:572)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:997)