Error in LiveSessionsPage

Description: java.lang.IllegalArgumentException: 'bytes' cannot be negative: -1
		Message: 'bytes' cannot be negative: -1
		
			org.apache.wicket.util.lang.Bytes.<init>(Bytes.java:111)
		
			org.apache.wicket.util.lang.Bytes.bytes(Bytes.java:124)
		
			org.apache.wicket.devutils.inspector.LiveSessionsPage$7.populateItem(LiveSessionsPage.java:163)
		
			org.apache.wicket.markup.html.list.ListView.onPopulate(ListView.java:523)
		
			org.apache.wicket.markup.repeater.AbstractRepeater.onBeforeRender(AbstractRepeater.java:124)
		
			org.apache.wicket.Component.beforeRender(Component.java:949)
		
			org.apache.wicket.MarkupContainer.onBeforeRenderChildren(MarkupContainer.java:1759)
		
			org.apache.wicket.Component.onBeforeRender(Component.java:3832)
		
			org.apache.wicket.Page.onBeforeRender(Page.java:789)
		
			org.apache.wicket.devutils.DevUtilsPage.onBeforeRender(DevUtilsPage.java:76)
		
			org.apache.wicket.Component.beforeRender(Component.java:949)
		
			org.apache.wicket.Page.renderPage(Page.java:991)
		
			org.apache.wicket.request.handler.render.WebPageRenderer.renderPage(WebPageRenderer.java:124)
		
			org.apache.wicket.request.handler.render.WebPageRenderer.respond(WebPageRenderer.java:195)
		
			org.apache.wicket.core.request.handler.RenderPageRequestHandler.respond(RenderPageRequestHandler.java:202)
		
			org.apache.wicket.request.cycle.RequestCycle$HandlerExecutor.respond(RequestCycle.java:910)
		
			org.apache.wicket.request.RequestHandlerExecutor.execute(RequestHandlerExecutor.java:63)
		
			org.apache.wicket.request.cycle.RequestCycle.execute(RequestCycle.java:294)
		
			org.apache.wicket.request.cycle.RequestCycle.processRequest(RequestCycle.java:255)
		
			org.apache.wicket.protocol.http.WicketFilter.processRequestCycle(WicketFilter.java:277)