PSA: if you're trying to use a Steam emulator to do offline/local/account-less multiplayer in a Windows game under WINE/etc., then replace it with the Goldberg emulator - as far as I can tell, it's the only Steam emulator that works under WINE and where the developers deliberately ensure that. Some games may need a specific build, see the included readme.
If you're using a pirated copy of a game under WINE/Proton and it crashes but according to ProtonDB it should work, then this is almost certainly also your issue - it came with a Steam emulator that doesn't work under WINE.
(There's also a Linux version of the emulator, but that is only useful for native Linux games - it will not work with Windows games under WINE.)
@joepie91 I even didn't know steam emulators exist! 
(Yes I know that sometimes, some other emulators work under some configurations for some games. The point here is that Goldberg works *consistently*.)