I have a save with around 200 days on it but I made it offline and I just now realized that I probably shouldn't have. I'm willing to have another go at it, except on my own online world but every time I create a new world and generate it with caves I get this error. I've pinpointed it to only caves, nothing else triggers this. I have no mods, my game file integrity is fine. I even tried making a world without caves and then adding them in later which is what I did for my 200 day server except last time i only did it cause i forgot i had to manually add caves at the start. The problem is; for some reason the game adds caves for me as soon as i leave the server anyways even though the box to automatically add caves is not checked which leads me to not be able to run the server anymore. I can't play on any server other than my offline one or possibly someone else's server, which I don't like.