Disconnected due to world corruption

I have 4 copies of my world and 3 of them plus the original are not working at the moment. Keep getting this message whenever I try opening the original world. Tried loading the first 2 copies and got the same message but then loaded the 3rd copy and it loaded up and the save file was pretty much where I was when I logged off last. It worked for about 30 minutes and then disconnected when my friend joined the game. Is there a fix to this? I don't want to load the 4th copy if its just going to corrupt.