Plutonium

Have the same problem, have created a thread as well and it was inconclusive.
clean reinstalled the game in steam and also repaired it
only sollution i can see is to install the version plutonium provides even having the game

RektInator i did that, thats how i got the dlc, should i just redo it?

anybody know a fix for this, its just annoying and i feel its just some missing files or something like that, thanks in advance