I had a world that me and my friend had made. My friend started playing with redstone and command blocks. There is an extremely fast clock that you can make with command blocks. (One command block set a block to air, the other command block setting that same space at redstone block). He then used that clock to power a third command block which spawned an ender dragon. The world is too laggy to do anything. I jiggle the mouse and it comes through about 2 1/2 minutes later. We were running version 1.10.2 (not snapshot)
I have tried opening the world in version 1.0, before there was redstone and ender dragons. That depended completely on whether the game deleted the "unknown" data. That did not work.
I would really like to have that world saved. I am at a loss as what to do. Thanks in advance.