Hmm, if we look at it logically we could say:
... your save is working on other, different, computers so the savefile seems not broken - no issue with savegame
So what's left?
(a) it could be an issue with the game itself and its handling of your (obviously really old) hardware, or
(b) a suddenly appeared hard- or software issue within your pc
If it's (a) Obsidian must have changed something important inside the program code, not just content related things, like cpu-, memory- or device-handling. I don't know if this is a plausible scenario, only Obsidian know what they changed.
The second and more likely option is that something's going wrong with your pc. Your hardware is rather old, and perhaps it's also possible to suffer a sudden "injury" of such parts. Perhaps your harddrive has failures, or the ram controller won't work very stable, hard to say at distance. Because you are almost the only one who is hit by such an issue i would strongly recommend to check your hardware first even if you think everything goes right except with PoE. E.g. overheating issues 'cause of dusted fans etc. can also cause such problems.