Save/load sucks! won't save!

okay… I’ll do that and tell u my results

got a new problem, not save/load…

omg… The game finally works the exact way I planned it to… AH GOD! Thank you so much bruh… Really thank you <3

same slots.
the name are exactly the same in both.

It looks like one of those weird errors.

Check the answer from Imagine-Games in https://answers.unrealengine.com/questions/337507/unknown-structure-error-when-cook.html. It may help.