Error code when trying to load game

Hello!

I can't get my game to load after downloading some CC yesterday. The mod I downloaded was the "Italia" world mod pack by Lijoue. I think I accidentally deleted the wrong ".world" files when trying to replace them with the mod files. Either way, I have since deleted that CC from my Mods folder, as well as any other CC I downloaded yesterday (the game was working fine with all my other mods the night before).

That didn't work, so I uninstalled and reinstalled the game completely. It will load fine with no mods, so the saves themselves are not corrupted I don't think, however if I put the mods folder back in, I am met with this error message:

I have tried to "double start" by not exiting the game after this message and instead trying to reload the game again, but that doesn't work.

My next move is to do the 50/50 method with my mods, however I'm curious if there is another reason this could be happening. Again, all the mods currently in my mods folder worked fine before I downloaded this CC yesterday.