Try to repair your windows first, when you can't uninstall and install it in the first place it sounds like an windows issue not an obs. Try open a commandline and try both commands for repair:
sfc /scannow
Dism /Online /Cleanup-Image /ScanHealth
When this won't help, which window uninstall method did you guys try? The App Uninstaller is still bugged under windows 10. It occurs rarely but maybe you are one of those cases. Try to uninstall over the old one via the control panel.
When you tried to update it via the newer executable and it didn#t work, did it gave you some error?