For first i thought it because my Mortal strike, it was about 4-5 errors after use Mortal strike (having a lethal) and it freeze after/before attack in face with hero attack or unit. So I removed Mortal strike from my deck and found next error with Heroic strike (having a lethal .____. ). I had no problem before last 2 patches (but about 95% of time i farmed 500 Warlock wins - has no errors.) But old version of Hearthbuddy not helped me too.
Today i had a error with my Priest vs Mage (having a lethal) with Holy smite in hand (maybe problem with lethal+spell?).
I think my wall of text above is useless =), so, because game is freezes, I'll just screenshot next 2-3 errors playing field in next 10-16 hours and add error text from Hearthstone(forgot this). I can add my priest game log, but i didn't think it helps. And i'll change language in game. Maybe you'll find some correlation.