Last modified: 2014-10-21 18:50:43 UTC
E.g. on https://www.mediawiki.org/wiki/VisualEditor - extra invisible characters at the end of each category name seems to be causing this
Change 166863 had a related patch set uploaded by Alex Monk: Follow normalisation response from category status query https://gerrit.wikimedia.org/r/166863
*** Bug 72303 has been marked as a duplicate of this bug. ***