RS: after new message in a forum

https://xyz.frentix.com/auth/RepositoryEntry/342753315/CourseNode/98066787504172/Identity/301302041
Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:64.0) Gecko/20100101 Firefox/64.0

**RedScreen**
<dispatchinfo>
	<componentinfo>
		<compname>cancel</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>cancel</command>
			<tostring>com:cancel,org.olat.core.gui.control.Event@ae7a2e99</tostring>
		</event>
	</componentinfo>
	<controllerinfo>
		<controllername>org.olat.core.gui.components.form.flexible.impl.elements.FormCancel$1</controllername>
		<controllername>org.olat.modules.fo.ui.MessageEditController</controllername>
		<controllername>org.olat.modules.fo.ui.MessageListController</controllername>
		<controllername>org.olat.modules.fo.ui.ForumController</controllername>
		<controllername>org.olat.course.nodes.fo.FOCourseNodeRunController</controllername>
		<controllername>org.olat.course.run.RunMainController</controllername>
		<controllername>org.olat.course.run.CourseRuntimeController</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:294)
   at org.olat.core.servlets.OpenOLATServlet.doPost(OpenOLATServlet.java:237)
   at javax.servlet.http.HttpServlet.service(HttpServlet.java:661)
>>> stack of 2.cause::java.lang.NullPointerException: null
-> at org.olat.modules.fo.ui.MessageListController.loadView(MessageListController.java:429)
   at org.olat.modules.fo.ui.MessageListController.reloadModel(MessageListController.java:315)
   at org.olat.modules.fo.ui.MessageListController.event(MessageListController.java:887)
   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.modules.fo.ui.MessageEditController.formCancelled(MessageEditController.java:557)
   at org.olat.core.gui.components.form.flexible.impl.FormBasicController.event(FormBasicController.java:412)
   at org.olat.core.gui.control.DefaultController.dispatchEvent(DefaultController.java:202)
   at org.olat.core.gui.components.AbstractComponent$1.run(AbstractComponent.java:240)