Hello @oggytheman, mainline Proton is expected to be backwards compatible with pre-existing wineprefixes, but any given release can't know what changes happen in the future. This mechanism already exists and is used when going from a newer Proton version to an older Proton version that doesn't know how to handle the newer wineprefix, however, there's an inherit risk of user data loss if the game doesn't use cloud saves.
The issue you've described here is that a third party build of Proton has made breaking changes somewhere, and hasn't clearly marking the wineprefix as newer or incompatible with mainline Proton. That's an issue to be evaluated by the maintainers of the third party build.
proton 10.0-4x1 2026-02
Feature Request
I confirm:
contain this feature already.
Description
There is currently an issue I’ve found with the game Phasmophobia that occurs when switching between different Proton versions. For example, when moving from Proton-CachyOS to Valve’s Proton 10.0-4, the game crashes. The same issue happens with Proton GE as well when switching to 10.0-4 mind you this happens only when going from these costume versions to 10.0-4 not the other way around.
This is likely caused by some registry-related issues. The problem is resolved if I regenerate the Proton prefix.
Because of this, my suggestion would be to regenerate the prefix automatically every time the Proton version is changed. There is already a system in place for this, but it currently only works when switching between major versions.
Justification [optional]
could potentially prevent similar issues like this with other games.
Risks [optional]
References [optional]
Phasmophobia crashes on startup when changing between Proton versions.