Stuck at switch to Riot Account screen in client

For the longest time now I could not click on links from the client. Stuff like going directly to a worlds stream when it started (from the notifications) or clicking links like champion trailers and such was not possible. I could click the link but nothing would happen. I never gave it any attention because, well, it was not needed to play the game. Now though, with the forced switch to Riot Accounts, I cannot click the red arrow to proceed to the registration. When I spam-click the red arrow eventually the client crashes.

I am basically stuck there, unable to play the game. I tried reinstalling the client but nothing changed. I cannot understand how that client passes tests. Every day I see like 20 different posts on here about client issues. How much of a spaghetti code does that damn thing have?

Anyway, any help would be appreciated.