I am running a server. I just created a new world and every time the server resets it stops and will say this. The server will not start until you enter yes in the command box.

The world was made on 1.13-JEID, but you are trying to start the server up with "1.12.2". This will most likely corrupt the world and you will lose it forever, which is a very long time

It was not the level.dat file. Going to keep looking into the problem on our end, maybe even check out a few forks of this mod to make sure it's not already been patched by someone.

I've been helping with patching the pack and I think I figured out the issue. I assume it's the level.dat file. I did some testing with the pack on my machine and it worked just fine. If I'm correct about this, it could be as easy as editing that file and re-uploading it to the server.