java.lang.AssertionError: BaseKit.install() incorrectly called from non-AWT thread.
        at org.netbeans.editor.BaseKit.install(BaseKit.java:503)
        at javax.swing.JEditorPane.setEditorKit(JEditorPane.java:980)
        at org.openide.text.CloneableEditor.initialize(CloneableEditor.java:209)
        at org.openide.text.CloneableEditor.getEditorPane(CloneableEditor.java:629)
        at org.openide.text.CloneableEditorSupport.getOpenedPanes(CloneableEditorSupport.java:850)
        at pmd.RunPMDAction.getSourceReader(RunPMDAction.java:329)
        at pmd.RunPMDAction.checkCookies(RunPMDAction.java:209)
        at pmd.RunPMDAction.performAction(RunPMDAction.java:267)
        at org.openide.util.actions.NodeAction$3.run(NodeAction.java:531)
        at org.netbeans.modules.openide.util.ActionsBridge$ActionRunnable.actionPerformed(ActionsBridge.java:81)
        at org.netbeans.core.ModuleActions.invokeAction(ModuleActions.java:74)
        at org.netbeans.modules.openide.actions.ActionsBridgeImpl.invokeAction(ActionsBridgeImpl.java:24)
        at org.netbeans.modules.openide.util.ActionsBridge$ActionRunnable.doRun(ActionsBridge.java:72)
        at org.netbeans.modules.openide.util.ActionsBridge$1.run(ActionsBridge.java:41)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:510)
[catch] at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:943)