Obviously the reports from mint are going to be more helpful to you, but try the proton versions that are reported to work* (actual versions, not experimental, that's a rolling version).
Ignore this, maybe...**
Very ignore this.
Yeah, this has happened to me recently ( I think it's a an updated grep thing?), I don't think it stopped things working, but I fixed it anyway ('cus it was my script that threw the error) EDIT: I wrote a fix for this, but it works with or without out it in this case, so...
**Before going any further, try "protontricks", it's winetricks for a specific steam app id (basically looks up what's installed and sets the wine prefix to steams prefix for it). If you have any winetricks version installed, the auto-update thing works, but will most likely be broken by your package manager next time it gets updated "officially".
Now, in the past I have got rid of "missing fonts" (your almost blank app windows issue) by installing the fonts (https://corefonts.sourceforge.net), used by the wine app I was trying to run, natively on my OS, then they are "just available to wine"; that said this was outside of proton and not ariel, so not sure if it will help here...
*If you want to use a GE proton version listed as working from protondb.com: