[xwiki-users] TRANSPORT_ERROR with no error message in Space Explorer Panel Application

Hi! XWiki 3.5.1 I installed manually Space Explorer Panel Application from http://extensions.xwiki.org/xwiki/bin/view/Extension/Space+Explorer+Panel+Ap... On attempt to make it running I receive Alarm Window with following warning: "Server returned TRANSPORT_ERROR with no error message." And "Loading" inside panel still turning. Any idea how to make it running? Kind regards, Dmitry