mcbigminer

I am trying to start a modpack server for a friend who had previously been playing a LAN game. He has sent me the "singleplayer" world file of said game and I am attempting to host it as a server. I have the correct version of 1.7.10 Forge and all of the mods that were being used in the previous game. It generates its own world file with no issues but when I replace the world file with the contents of the old world, it gives this: When you join the server, the world is correct but some chunks are corrupted and some blocks have missing textures. It would be awesome if somebody knew the fix to this as I have found nothing about this online. EDIT: sorry, the spoiler tag is broken for some reason. The contents are still there, you just have to scroll.