I've been playing since alpha and my main save game don't work anymore after 1.7 update! I can open it but it lags like hell, 1-2 FPS, unlike new worlds that I created for testing.
My backup works only one time. After I save, exit and try to load the game again I can't play anymore. The only way to keep the game working is to don't get near the chunk error. I can play in my mines or far from the error, but as soon as the chunk error gets in my line of sight the game becomes unplayable after the first save and exist.
I think it is related to a chunk error that have appeared near my base.
What can I do? I have already done a java update...
UPDATE: Sometimes the save works, other times it loads but becomes unplayable. That happens in an almost random pattern...