I was told that notifications do not work at Mac OS for @Mates at cswiki in Safari (in Chrome everything is normal). They just do not open. At other wikis all works as normally. Safemode, inkognito browser and another on-wiki user made no difference. I tried it at my own Mac (I was logged in as Wikipedista XY), everything worked normally.
Several other things do not work (for example the edit toolbar isn't showed). Let me know if I should create other tasks for those other things or we'll use this one as all-in-one. As it is significantly marking wiki-work harder, marking as UBN.