I have never had a problem loading old saves, but then I don't use mods or anything either, might be why...When a new update comes out, I always install it separately, then check if I am able to load my old saves to the newer version before deleting the previous. I found this game sometime in October 2019 and have never had problems with it on my PC running Win 10.
Every update, I move my screenshots, files, and saves to the new folder, and then delete the old (sometimes the appdata folder too, I hate filling up C drive with that stuff).