Old client bugging and looks like from S2

I downloaded game after formatting computer. Then while launching legacy client (new one is too laggy for my pc) this one showed up. I cant click any buttons on Bottom,left corner and when sb is texting me i hear new message, tho i dont see it and i cant check what it was about. Anyone pls help me i really want to play with my friends, but i cant :/ (new client works normally tho in champ sellect i just have like 0.2FPS)