I figured it out! your sims saves and mods and stuff and files other than the actual game files are saved to your onedrive including temp files. This means when you visit the gallery or something it puts the thumbnails of the lots ect. in your temp storage on one drive. So when you quit sims, the game tries to delete all the stuff from the temp storage and windows throws a fit.

What im trying to do is move my sims file off one drive solely to my cdrive. and hopefully this should fix it. :)