Board Thread:General Discussion/@comment-29542250-20160829012137/@comment-26843745-20160829055805

I presume I have found the infobox template in question. The collapse not working there is due to collapsible collapsed being used to make the content collapse - both collapsible and collapsed should have mw- added before them. Hence, in order to get the collapse work properly, replace collapsible collapsed with mw-collapsible mw-collapsed.