Some features of the app are disabled as it launched from another application

I have seen a few variations of this problem, and I apologise for the repetition, but none of the solutions given in those posts have worked for me.

I am trying to play the Sims 4, and each time I try to launch the game, the EA app will open and a variation of the message 'some features have been disabled because EA launched from another application' appears before the app closes itself and reloads. I have tried signing out and back into my EA account, clearing the cache, deleting and re-installing EA, deleting and reinstalling the sims, running EA and Steam as administrators, including the sims as an exception for my anti-virus, but nothing has helped.

I was playing it just fine like a week ago.