Are you running it via a shortcut with +path=".." at the end of the target? Maybe try reinstalling the runtimes in Support\Runtimes (all 4 of them).
Answered on discord, so for those following along at home; copy and paste this in the search box bottom left of windows... Code: REG DELETE "HKCU\SOFTWARE\Image Space Incorporated\rFactor2 Mod Manager" /F