When trying to add pages in aggregate groups nothing happens on button "Add". When tracing it says "Unknown dependency jquery.chosen" I can see in change log that something about this was added in August release. Some .js files that I am missing?
Topic on Extension talk:Translate
What version of MediaWiki are you using?
1.21.3 and MLEB 2013.10. I manually downloaded chosen plugin for jquery and added the files in mediawiki/resources and and added references so now it works but maybe the files should be included I Translate extension reource files?
This issue has been resolved in MLEB 2013.11. Thanks for reporting it!