I’m afraid I haven’t encountered this issue before. I don’t have any problems running Python Mode on my Windows machine (same Processing and OS as far as I can tell). I have Processing running from a folder on my desktop; I don’t use OneDrive.
Maybe it’s your code? Have you tried creating a very simple sketch – like, a one-liner with just square(10, 10, 10). See if that runs or if you get the same error.
Maybe somebody else on the forum could help …