javax.swing.text.BadLocationException: Invalid offset=53221 not within <0, 53218>
        at org.netbeans.editor.Utilities.checkOffsetValid(Utilities.java:1348)
        at org.netbeans.editor.Utilities.getLineOffset(Utilities.java:614)
        at org.netbeans.modules.css.gsf.CSSStructureScanner$2.visit(CSSStructureScanner.java:186)
        at org.netbeans.modules.css.parser.SimpleNode.visitChildren(SimpleNode.java:168)
        at org.netbeans.modules.css.parser.SimpleNode.visitChildren(SimpleNode.java:169)
        at org.netbeans.modules.css.gsf.CSSStructureScanner.folds(CSSStructureScanner.java:197)
        at org.netbeans.modules.gsfret.editor.fold.GsfFoldManager$JavaElementFoldTask.addTree(GsfFoldManager.java:435)
        at org.netbeans.modules.gsfret.editor.fold.GsfFoldManager$JavaElementFoldTask.scan(GsfFoldManager.java:428)
        at org.netbeans.modules.gsfret.editor.fold.GsfFoldManager$JavaElementFoldTask.gsfFoldScan(GsfFoldManager.java:349)
        at org.netbeans.modules.gsfret.editor.fold.GsfFoldManager$JavaElementFoldTask.run(GsfFoldManager.java:321)
        at org.netbeans.modules.gsfret.editor.fold.GsfFoldManager$JavaElementFoldTask.run(GsfFoldManager.java:273)
        at org.netbeans.napi.gsfret.source.Source$CompilationJob.run(Source.java:1409)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
        at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
        at java.util.concurrent.FutureTask.run(FutureTask.java:138)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:885)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:907)
        at java.lang.Thread.run(Thread.java:619)