Worker exited due to java.util.ConcurrentModificationException

java.util.ConcurrentModificationException
	at java.util.HashMap$HashIterator.nextNode(HashMap.java:1437)
	at java.util.HashMap$EntryIterator.next(HashMap.java:1471)
	at java.util.HashMap$EntryIterator.next(HashMap.java:1469)
	at de.sgalinski.typoscript.editor.utility.TypoScriptFileTreeUtility.compareAllFileTreesIntoOneWithoutCurrentFileTree(TypoScriptFileTreeUtility.java:220)
	at de.sgalinski.typoscript.editor.utility.TypoScriptFileTreeUtility.<init>(TypoScriptFileTreeUtility.java:90)
	at de.sgalinski.typoscript.editor.usability.TypoScriptGoToDeclarationHandler.getTypoScriptNode(TypoScriptGoToDeclarationHandler.java:113)
	at de.sgalinski.typoscript.editor.usability.TypoScriptGoToDeclarationHandler.getGotoDeclarationTargets(TypoScriptGoToDeclarationHandler.java:42)
	at com.intellij.codeInsight.navigation.actions.GotoDeclarationAction.findTargetElementsNoVS(GotoDeclarationAction.java:245)
	at com.intellij.codeInsight.navigation.CtrlMouseHandler.a(CtrlMouseHandler.java:531)
	at com.intellij.codeInsight.navigation.CtrlMouseHandler.a(CtrlMouseHandler.java:510)
	at com.intellij.codeInsight.navigation.CtrlMouseHandler.access$2600(CtrlMouseHandler.java:106)
	at com.intellij.codeInsight.navigation.CtrlMouseHandler$TooltipProvider.a(CtrlMouseHandler.java:846)
	at com.intellij.codeInsight.navigation.CtrlMouseHandler$TooltipProvider.access$2500(CtrlMouseHandler.java:786)
	at com.intellij.codeInsight.navigation.CtrlMouseHandler$TooltipProvider$1.performInReadAction(CtrlMouseHandler.java:831)
	at com.intellij.openapi.progress.util.ReadTask$1.compute(ReadTask.java:70)
	at com.intellij.openapi.progress.util.ReadTask$1.compute(ReadTask.java:67)
	at com.intellij.openapi.application.impl.ApplicationImpl.runReadAction(ApplicationImpl.java:966)
	at com.intellij.openapi.progress.util.ReadTask.runBackgroundProcess(ReadTask.java:67)
	at com.intellij.openapi.progress.util.ProgressIndicatorUtils$7.compute(ProgressIndicatorUtils.java:227)
	at com.intellij.openapi.progress.util.ProgressIndicatorUtils$7.compute(ProgressIndicatorUtils.java:223)
	at com.intellij.openapi.progress.impl.CoreProgressManager$3.run(CoreProgressManager.java:162)
	at com.intellij.openapi.progress.impl.CoreProgressManager$2.run(CoreProgressManager.java:142)
	at com.intellij.openapi.progress.impl.CoreProgressManager.a(CoreProgressManager.java:446)
	at com.intellij.openapi.progress.impl.CoreProgressManager.executeProcessUnderProgress(CoreProgressManager.java:392)
	at com.intellij.openapi.progress.impl.ProgressManagerImpl.executeProcessUnderProgress(ProgressManagerImpl.java:54)
	at com.intellij.openapi.progress.impl.CoreProgressManager.runProcess(CoreProgressManager.java:127)
	at com.intellij.openapi.progress.impl.CoreProgressManager.runProcess(CoreProgressManager.java:159)
	at com.intellij.openapi.progress.util.ProgressIndicatorUtils.a(ProgressIndicatorUtils.java:223)
	at com.intellij.openapi.progress.util.ProgressIndicatorUtils.access$000(ProgressIndicatorUtils.java:45)
	at com.intellij.openapi.progress.util.ProgressIndicatorUtils$6$2.run(ProgressIndicatorUtils.java:188)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)