"Fatal exception of type MWException" as answer for "Special:ManageMessageGroups" page

I don't understand what you mean with "never publishes".

I mean Firefox keeps waiting for the page to come and meanwhile only shows a white page.

I tried to find out if it was coming from my configuration, so I installed a clean MW 1.21.2 with the extensions Translate and UniversalLanguageSelector (Both Version MLEB 2013.10), and the problem doesn't come up again.

Maybe I could reset the stats by suppressing all translated pages (only 2 for the moment) ?

Or is there a better way ?

It is unclear what you are asking now.

Dieudo, simple update problems for stats pages are solved as usual in MediaWiki, by appending action=purge (and then refreshing a few times without action=purge in the URL, to fill the stats); more complex problems like those you describe are similar to an issue related to local browser cache (please hard refresh the page) which we had on our wikis too and was IIRC solved in more recent code/configuration, so please paste relevant configuration from your LocalSettings.php if nothing solves it.

Thank you to both of you. I'll wait 2013-11-29, when MW 1.22 is released, to upgrade my wiki, guessing this should solve the problem : )

Thank you to both of you. I'll wait 2013-11-29, when MW 1.22 is released, to upgrade my wiki, guessing this should solve the problem : )