unable to play, now it asks me for another key

[oldage]

Alright so, a week or so ago I could play fine, earlier this week the game did not allow me to click solo or multiplayer (I sent a ticket for that, still waiting for an actual answer) and today I try again, only for it to ask me for ANOTHER key.

I give in my key I've gotten in my email when I purchased the game and the game said the key was not registered... even though I could play just fine some time ago.

I was gifted the game and the original buyer says there are no problems on his end.

Any ideas?