Proton: How to trigger proton reinstall?

[Elkasitu]

I tried deleting the Proton 3.7 Beta dir inside steamapps/common and then disabling and re-enabling proton from the Steam UI but that didn't work

[aeikum]

Try validating the local files for a game that uses it. Smaller games will validate more quickly.

[Elkasitu]

That did it, thanks!

[reavertm]

That alone doesn't work until proton related appmanifest_xxx.acf file from library folder is also removed. Only then Steam successfully sees proton as missing and re-fetches it.