QTI 2.1: RS detaching a question in test from the pool

2018-06-19 10:34:45,740 [ajp-nio2-8061-exec-336] ERROR OLATRuntimeException - OLAT::ERROR ^%^ N61-E75 ^%^ org.olat.core.logging 
https://xyz.openolat.com/auth/RepositorySite/0/Favorits/0
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/11.1.1 Safari/605.1.15

**RedScreen**

<dispatchinfo>
	<componentinfo>
		<compname>ffo_main_null</compname>
		<compclass>org.olat.core.gui.components.form.flexible.impl.FormWrapperContainer</compclass>
		<extendedinfo>n/a</extendedinfo>
		<event>
			<class&gt;org.olat.core.gui.components.form.flexible.impl.FormEvent</class&gt;
			<command>done</command>
			<tostring>com:done,org.olat.core.gui.components.form.flexible.impl.FormEvent@2f23a1</tostring>
		</event>
	</componentinfo>
	<controllerinfo>
		<controllername>org.olat.ims.qti21.ui.editor.PoolEditorController</controllername>
		<controllername>org.olat.ims.qti21.ui.editor.AssessmentItemEditorController</controllername>
		<controllername>org.olat.ims.qti21.ui.editor.AssessmentTestComposerController</controllername>
		<controllername>org.olat.ims.qti21.ui.QTI21RuntimeController</controllername>
		<controllername>org.olat.core.commons.fullWebApp.BaseFullWebappController</controllername>
	</controllerinfo>
</dispatchinfo>

>>> stack of 1.cause::org.olat.core.logging.OLATRuntimeException: null
-> at org.olat.core.gui.exception.ExceptionWindowController.<init>(ExceptionWindowController.java:116)
   at org.olat.core.gui.exception.MsgFactory.createMessageChiefController(MsgFactory.java:57)
   at org.olat.core.gui.exception.MsgFactory.createMessageChiefController(MsgFactory.java:46)
   at org.olat.core.gui.components.Window.dispatchRequest(Window.java:589)
   at org.olat.core.gui.components.Window.doDispatchRequest(Window.java:282)
   at org.olat.core.gui.components.AbstractComponent.dispatchRequest(AbstractComponent.java:193)
   at org.olat.dispatcher.AuthenticatedDispatcher.processValidDispatchURI(AuthenticatedDispatcher.java:273)
   at org.olat.dispatcher.AuthenticatedDispatcher.execute(AuthenticatedDispatcher.java:190)
   at org.olat.core.servlets.OpenOLATServlet.executeUserRequest(OpenOLATServlet.java:287)
   at org.olat.core.servlets.OpenOLATServlet.doPost(OpenOLATServlet.java:230)
   at javax.servlet.http.HttpServlet.service(HttpServlet.java:661)
>>> stack of 2.cause::java.lang.NullPointerException: null
-> at org.olat.ims.qti21.ui.editor.AssessmentTestComposerController.doReloadItem(AssessmentTestComposerController.java:893)
   at org.olat.ims.qti21.ui.editor.AssessmentTestComposerController.doDetachItemFromPool(AssessmentTestComposerController.java:887)
   at org.olat.ims.qti21.ui.editor.AssessmentTestComposerController.event(AssessmentTestComposerController.java:454)
   at org.olat.core.gui.control.DefaultController$1.run(DefaultController.java:246)
   at org.olat.core.logging.activity.ThreadLocalUserActivityLoggerInstaller.runWithUserActivityLogger(ThreadLocalUserActivityLoggerInstaller.java:108)
   at org.olat.core.gui.control.DefaultController.dispatchEvent(DefaultController.java:243)
   at org.olat.core.gui.control.DefaultController.fireEvent(DefaultController.java:190)
   at org.olat.ims.qti21.ui.editor.AssessmentItemEditorController.event(AssessmentItemEditorController.java:546)
   at org.olat.core.gui.control.DefaultController$1.run(DefaultController.java:246)
   at org.olat.core.logging.activity.ThreadLocalUserActivityLoggerInstaller.runWithUserActivityLogger(ThreadLocalUserActivityLoggerInstaller.java:108)
   at org.olat.core.gui.control.DefaultController.dispatchEvent(DefaultController.java:243)