It kind of sounds like there may be some issues with another program you have installed interfering with OOTP and causing some data corruption. Anti-malware and anti-virus programs are especially likely to cause those sort of issues. So it's always a good idea to whitelist (exclude) OOTP in those programs.
It seems like you also have a second issue of some old files left from before the uninstall that are directing the game to a non-existent data path.
Given this is fairly complex, the quickest way for us to get you help, would be if you can submit a support ticket (
https://support.ootpdevelopments.com/portal/en/home or email
support@ootpdevelopments.com) so the support guys can work with you directly on checking this out.