Last modified: 2013-08-22 14:35:47 UTC
It is currently not possible to switch the language version on test.wikidata.org which is a core functionality of the site. When trying to switch to another language via ULS nothing happens.
Patch in review https://gerrit.wikimedia.org/r/#/c/79452/
Moving to highest/critical as this is now live on wikidata.org it seems and breaking a core functionality of the site.
I completely missed that the version of ULS in 1.22wmf13 contained the regression but not the fix. I've updated ULS to master in 1.22wmf13 which fixes this and few other bugs.