This is version 0.35, yes? You'll need to apply the patch titled "(UPDATED) Old Save Compatibility Patch" in the mega folder and apply that to your game. You'll also want to enable the "Dungeon 5 Compatibility Patch" from the debug item after doing so. A plugin that was added in version 0.35 made old saves compatible, so I had to edit the code of the plugin and add it back in to fix that.