Hi everyone,
We've just found that XE 1.8.1 is having some GWT service
initialization issue in multiwiki mode. All applications using the
XWiki GWT service fail on XE 1.8.1 (in multiwiki mode only).
More specifically this will affects users in multiki mode and using
the new WYSIWYG editor or XWiki Watch (both using GWT Services).
For those users we recommend to wait for XE 1.8.2 which is planned for
early next week (week of the 20th of April).
Sorry for the inconvenience.
-Vincent on behalf of the XWiki dev team