Entities disappearing?

[Gladoshatesyou]

Oh my, that's a lot of errors.
What have you been doing? Have you been modifying some of the game's files? Used any custom entities? I know I saw someone here just a few days ago mentioning this XML error. Don't remember where that thread went, but they did fix it. Perhaps something similar can help here, though there seem to be more than just that.

Yes, I did. I made a very foolish Mistake and copied most of Machine For Pigs Files (Because I saw a thing where they said it was a way to make custom stories for it) and it worked... Sorta. It just crashed sometimes but I deleted some files and such. So, yeah.