Details version: R9824
WoW version: 9.2.7

This only happens with one specific ability, which is Mindbender's AA.
It appears as just broken text when hovering over my damage bar, while when opening the encounter desc the ability name is in russian.

here's how it looks when mouse hovering

and here's how it looks in the encounter desc

I think it should just appear in english, not sure why it doesn't.

upd: reinstalling the addon fixed everything