I'm using Windows 10, and I have confirmed that the game works fine without mods. The version of the game is the current full download of the game (I did the patch first, but had the same problem, so I tried the full download, which only worked after I had deleted my save).
That is the error the game gives me once I try to leave the title screen.
At this moment, I started deleting mods out of the folder to see which one is causing the problem. After trial and error, I deleted the Shared PC mod, and that allowed the game to work. My game is running just fine now. I should've done this in the first place, but alas, I was late at night. (Huh... the page didn't update, so I didn't see these replies... aw well. At least the problem is fixed!