Might need to try another save then, it might just not like where you were.I've just moved from 11.2 to 12.4 and my save game won't load, it crashes out in 000statements.rpy. I tried 12.2. same deal :-(
The other thing could be that if you were using a mod before and are not using it now, you need to have it back.
Have you tried it? Ren'Py is not a really hardcore thing... You should not really need a good system to run it, as long as you have the space for it.Hmm.. it is sad but i guess it cant be helped. Been playing since v10 and i already tried v12 (joiplay thingy) and always force closed(i play on android). I cant play on my laptop cus its already outdated(old laptop). I think i should wait a lil more to enjoy this game again.
Good luck for ur game bro