ClassCastException when trying to Import an invalid XAR

Detailed information:
    Error number 11015 in 11: Exception while importing
com.xpn.xwiki.XWikiException: Error number 11015 in 11: Exception while importing
	at com.xpn.xwiki.web.ImportAction.render(ImportAction.java:106)
	at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:348)
	at com.xpn.xwiki.web.XWikiAction.execute(XWikiAction.java:149)
	at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:425)
	at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:228)
	at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
	at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:462)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
	at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:769)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1667)
	at com.xpn.xwiki.web.ActionFilter.doFilter(ActionFilter.java:115)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1650)
	at org.xwiki.wysiwyg.server.filter.ConversionFilter.doFilter(ConversionFilter.java:127)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1650)
	at org.xwiki.container.servlet.filters.internal.SetHTTPHeaderFilter.doFilter(SetHTTPHeaderFilter.java:63)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1650)
	at com.xpn.xwiki.plugin.webdav.XWikiDavFilter.doFilter(XWikiDavFilter.java:66)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1650)
	at org.xwiki.container.servlet.filters.internal.SavedRequestRestorerFilter.doFilter(SavedRequestRestorerFilter.java:208)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1650)
	at org.xwiki.container.servlet.filters.internal.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:111)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1650)
	at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:583)
	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)
	at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:577)
	at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:223)
	at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1125)
	at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:515)
	at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185)
	at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1059)
	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
	at org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:215)
	at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:110)
	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
	at org.eclipse.jetty.server.Server.handle(Server.java:497)
	at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:311)
	at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:248)
	at org.eclipse.jetty.io.AbstractConnection$2.run(AbstractConnection.java:540)
	at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:610)
	at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:539)
	at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.ClassCastException: java.lang.String cannot be cast to org.xwiki.model.reference.EntityReference
	at com.xpn.xwiki.web.ImportAction.importPackageFilterStream(ImportAction.java:360)
	at com.xpn.xwiki.web.ImportAction.importPackage(ImportAction.java:142)
	at com.xpn.xwiki.web.ImportAction.render(ImportAction.java:103)
	... 41 more