Same thing happens to me and the proposed solution didn't really work.
Here's the breakdown of the matter of things I discovered so far:
1. Old save won't load with the mods I used before installed.
2. Won't load with mods unchecked
3. Will load with mods actually removed from the mods folder (I guess this won't trigger the "save was made with these mods installed that are now disabled" check)
4. After saving the game with mods removed from folder and then readding the mods but keeping them unchecked the save will load.
5. After that any mod enabled will make loading impossible again (ctd)
6. New game works fine with any mods enabled
Feels like dead end unless I am ready to play completely without mods and I am not.
