I notice with low-end PCs some folks run into that problem, tho someone was able to fix it themselves. Somehow the save file got corrupted but if you delete it manually, the game will create a new save the next time you boot it up and it'll function properly. Your save file is located in AppData\Local\AtC_BB\Saved\SaveGames. The .sav file is the one you're going to want to move or delete. As for a 32 Bit version, that is coming very soon!