Cannot delete a deleted question in pool

2017-06-22 16:36:53,249 [ajp-nio2-8013-exec-12] ERROR OLATRuntimeException - OLAT::ERROR ^%^ N13-E30 ^%^ org.olat.core.logging
https://xyz.frentix.com/auth/QPool/0/My/0 ^%^ Mozilla/5.0 (Windows NT 10.0; WOW64; rv:54.0) Gecko/20100101 Firefox/54.0

**RedScreen** Unable to find org.olat.modules.qpool.model.QuestionItemImpl with id 176194756

<dispatchinfo>
	<componentinfo>
		<compname>link_0</compname>
		<compclass>org.olat.core.gui.components.link.Link</compclass>
		<extendedinfo>n/a</extendedinfo>
		<event>
			<class&gt;org.olat.core.gui.control.Event</class&gt;
			<command>link_0</command>
			<tostring>com:link_0,org.olat.core.gui.control.Event@be46a54a</tostring>
		</event>
	</componentinfo>
	<controllerinfo>
		<controllername>org.olat.core.gui.control.generic.modal.DialogBoxController</controllername>
		<controllername>org.olat.modules.qpool.ui.QuestionListController</controllername>
		<controllername>org.olat.modules.qpool.ui.QuestionPoolMainEditorController</controllername>
		<controllername>org.olat.core.commons.fullWebApp.BaseFullWebappController</controllername>
	</controllerinfo>
</dispatchinfo>

>>> stack of 1.cause::org.olat.core.logging.OLATRuntimeException: Unable to find org.olat.modules.qpool.model.QuestionItemImpl with id 176194756
-> 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:549)
   at org.olat.core.gui.components.Window.doDispatchRequest(Window.java:242)
   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:292)
   at org.olat.core.servlets.OpenOLATServlet.doPost(OpenOLATServlet.java:235)
   at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
>>> stack of 2.cause::javax.persistence.EntityNotFoundException: Unable to find org.olat.modules.qpool.model.QuestionItemImpl with id 176194756
-> at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$JpaEntityNotFoundDelegate.handleEntityNotFound(EntityManagerFactoryBuilderImpl.java:158)
   at org.hibernate.internal.SessionImpl$IdentifierLoadAccessImpl.doGetReference(SessionImpl.java:2745)
   at org.hibernate.internal.SessionImpl$IdentifierLoadAccessImpl.getReference(SessionImpl.java:2722)
   at org.hibernate.internal.SessionImpl.getReference(SessionImpl.java:3470)
   at org.olat.modules.qpool.manager.QuestionItemDAO.delete(QuestionItemDAO.java:228)
   at org.olat.modules.qpool.manager.QuestionPoolServiceImpl.deleteItems(QuestionPoolServiceImpl.java:126)
   at org.olat.modules.qpool.ui.QuestionListController.doDelete(QuestionListController.java:886)
   at org.olat.modules.qpool.ui.QuestionListController.event(QuestionListController.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)