Sounds like it was an outdated file problem then. We're sorry that the updates cause these problems, but the only way to prevent it is to stop all development or to disable the save function. And obviously people don't really want either situation to occur. So unfortunately it's an inconvenience that people will have to put up with for a while - that, or if you've got a save file you really want to keep, make a backup of the game before you update it. Just copy over the entire game folder and prevent it from performing updates, then let your second copy perform updates. That way you've got both an up-to-date version and a copy of the old files if your save is no longer compatible.
