Not the first time I have this problem with Dead by Daylight.
Previous patch got me this error again - "EAC client cannot be instantiated.".

I have deleted the game, installed, tried to clean up folders, verified files etc - occasionally it worked.

Now I have new patch, right after game doesn't work again.
I tried all the stuff, which helped previously - still not working.

I have googled this error - many topics across many years.
It's just a problem from the developer side. Like many bugs in the game.