BadLocationException when typing too fast with live completer enabled

[amlajmi]

!ENTRY org.eclipse.rap.ui 4 0 2017-10-16 23:52:22.623 !MESSAGE Unhandled event loop exception !STACK 0 java.lang.IllegalArgumentException: Argument not valid at org.eclipse.swt.SWT.error(SWT.java:3694) at org.eclipse.swt.SWT.error(SWT.java:3631) at org.eclipse.swt.SWT.error(SWT.java:3602) at org.dslforge.styledtext.DefaultContent.error(DefaultContent.java:652) at org.dslforge.styledtext.DefaultContent.getOffsetAtLine(DefaultContent.java:622) at org.dslforge.styledtext.BasicText.getOffsetAtPosition(BasicText.java:1252) at org.dslforge.texteditor.BasicTextEditor$2.verifyKey(BasicTextEditor.java:155) at org.dslforge.styledtext.BasicText$BasicTextListener.handleEvent(BasicText.java:128) at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:109) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:687) at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:594) at org.eclipse.swt.widgets.Display.executeNextEvent(Display.java:1217) at org.eclipse.swt.widgets.Display.runPendingMessages(Display.java:1198) at org.eclipse.swt.widgets.Display.safeReadAndDispatch(Display.java:1181) at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:1173) at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2733) at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2694) at org.eclipse.ui.internal.Workbench.access$5(Workbench.java:2530) at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:701) at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:336) at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:684) at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:157) at org.codingpark.piraterobot.demo.CodeGameWorkbench.createUI(CodeGameWorkbench.java:35) at org.eclipse.rap.rwt.internal.lifecycle.RWTLifeCycle.createUI(RWTLifeCycle.java:177) at org.eclipse.rap.rwt.internal.lifecycle.RWTLifeCycle$UIThreadController.run(RWTLifeCycle.java:290) at java.lang.Thread.run(Thread.java:745) at org.eclipse.rap.rwt.internal.lifecycle.UIThread.run(UIThread.java:107)