https://bugs.winehq.org/show_bug.cgi?id=47832
--- Comment #11 from Jeff Zaroyko jeffz@jeffz.name --- (In reply to Joe Davison from comment #10)
This was fixed in 4.21 but it appears there's been a regression since. The last version of Wine that Mod Organizer's USVFS is functional in, as far as I can tell, is 5.0.
At any rate, I think this bug should be reopened as there definitely seems to be a regression.
Please file a new bug for the regression occurred after being fixed. This one would only be reopened if it was never actually fixed. If you can help with regression testing that would be super: https://wiki.winehq.org/Regression_Testing