java.lang.NullPointerException
        at org.openide.filesystems.FileUtil.toFile(FileUtil.java:501)
        at org.netbeans.modules.xml.schema.completion.util.CompletionContextImpl.specialCompletion(CompletionContextImpl.java:507)
        at org.netbeans.modules.xml.schema.completion.util.CompletionContextImpl.initModels(CompletionContextImpl.java:485)
        at org.netbeans.modules.xml.schema.completion.CompletionQuery.getCompletionItems(CompletionQuery.java:96)
        at org.netbeans.modules.xml.schema.completion.CompletionQuery.query(CompletionQuery.java:79)
        at org.netbeans.spi.editor.completion.support.AsyncCompletionTask.run(AsyncCompletionTask.java:218)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:561)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:986)