Adding mods/ reordering mods on an existing save is bugged for the most part, there is a more or less solution its kinda shitty but whatever, i've postes it on eml topic
Doesnt really work for slu tho
Viewing post in Mod: Conquest Tweaks
to be clear, even saves I make with the kennels mod, for example, can’t be loaded at all. I can still make a new game where the kennel works but if I try and load that same game I can’t. But that’s good to know on the existing vanilla saves, I’m glad I left those alone
Edit: found the answer, I was on 6.6a instead of c