"and changed my startup location" stands out to me.
There is likely a configuration file still there pointing to where the game ought to be and that likely survived the uninstall/reinstall. Follow the link on this thread and see if you can find the file. It's just a guess but based on what you said you did and having seen this come up before in various ways after people move stuff, it's probably worth a shot.
https://forums.ootpdevelopments.com/...ghlight=config