RS if a media is not available to a blog

2013-10-21 09:54:28,381 [ajp-apr-8005-exec-13] ERROR OLATRuntimeException - OLAT::ERROR ^%^ N5-E11 ^%^ org.olat.core.logging ^%^
https://xxx/olat/auth/1%3A1%3A5005521158%3A2%3A0%3Acid%3Acmd.repo.course/ ^%^
Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.1 (KHTML, like Gecko) Maxthon/4.1.2.4000 Chrome/26.0.1410.43 Safari/537.1
**RedScreen** null ::_::
<dispatchinfo>
	<componentinfo>
		<compname>feed.edit</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>feed.edit</command>
			<tostring>com:feed.edit,org.olat.core.gui.control.Event@9b4c9479</tostring>
		</event>
	</componentinfo>
	<controllerinfo>
		<controllername>org.olat.modules.webFeed.ui.FeedMainController</controllername>
		<controllername>org.olat.course.run.RunMainController</controllername>
		<controllername>org.olat.core.commons.fullWebApp.BaseFullWebappController</controllername>
		<controllername>org.olat.core.commons.chiefcontrollers.controller.simple.SimpleBaseController</controllername>
		<controllername>org.olat.core.commons.chiefcontrollers.BaseChiefController</controllername>
	</controllerinfo>
</dispatchinfo>
>>> stack of 1.cause::org.olat.core.logging.OLATRuntimeException: null
-> at org.olat.core.gui.exception.ExceptionWindowController.<init>(ExceptionWindowController.java:107)
   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:508)
   at org.olat.core.gui.components.Window.doDispatchRequest(Window.java:226)
   at org.olat.core.gui.components.Component.dispatchRequest(Component.java:192)
   at org.olat.dispatcher.AuthenticatedDispatcher.execute(AuthenticatedDispatcher.java:227)
   at org.olat.core.dispatcher.DispatcherAction.execute(DispatcherAction.java:154)
   at org.olat.core.servlets.OLATServlet.doPost(OLATServlet.java:155)
   at org.olat.core.servlets.OLATServlet.doGet(OLATServlet.java:128)
   at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
>>> stack of 2.cause::java.lang.NullPointerException: null
-> at org.olat.core.util.vfs.VFSMediaResource.getSize(VFSMediaResource.java:78)
   at org.olat.core.util.vfs.VFSMediaResource.getInputStream(VFSMediaResource.java:83)
   at org.olat.core.gui.components.image.ImageComponent.setMaxWithAndHeightToFitWithin(ImageComponent.java:144)
   at org.olat.modules.webFeed.ui.FeedFormController.setImage(FeedFormController.java:222)
   at org.olat.modules.webFeed.ui.FeedFormController.initForm(FeedFormController.java:282)
   at org.olat.core.gui.components.form.flexible.impl.FormBasicController.initForm(FormBasicController.java:215)
   at org.olat.modules.webFeed.ui.FeedFormController.<init>(FeedFormController.java:94)
   at org.olat.modules.webFeed.ui.FeedMainController.event(FeedMainController.java:187)
   at org.olat.core.gui.control.DefaultController.dispatchEvent(DefaultController.java:195)
   at org.olat.core.gui.components.Component$1.run(Component.java:238)
   at org.olat.core.logging.activity.ThreadLocalUserActivityLoggerInstaller.runWithUserActivityLogger(ThreadLocalUserActivityLoggerInstaller.java:108)