It happened to me...
It can be solved going to Library--»Tools and manually installing Proton 3.16 beta.

excellent, let's hope everyone reads this thread.
Hello @Niroc, this issue is already being tracked at https://github.com/ValveSoftware/steam-for-linux/issues/6093. Closing as a duplicate.
proton 3.16x2 2019-02proton 3.16-7x1 2019-02DXVK_HUD=full`x1 2019-02DXVK_HUD=version`x1 2019-02
Compatibility Report
System Information
I confirm:
Symptoms
I noticed that Proton 3.16-7 updated to DXVK 0.96 so I thought I'd try the
DXVK_HUD=fulloption introduced in DXVK 0.95 but, it didn't work. So, I triedDXVK_HUD=versionwhich revealed that I was running DXVK 0.94.I did double check that the games are set to run using 3.16-7...

I then checked the "/home/niroc/.steam/steam/steamapps/common/Proton 3.16 Beta/" folder and noticed that files haven't had their Date Modified stamp updated this month.
So, I think that it's still 3.16-6. If this has happened to anyone else then you may be getting erroneous error reports for things that have been fixed in Proton 3.16-7.
I have tried verifying integrity of games files, restarting steam, disabling and enable proton... to no avail
Reproduction
Use Proton 3.16-7
Proton log for DS3
steam-374320.log