Not sure. One way to check is to set the values of both structures and save it all in one single Save Game instead of two.
So, basically, connect the out of “Set members in MainStruct” into “Continuing Saving”.
okay… I’ll do that and tell u my results
omg… The game finally works the exact way I planned it to… AH GOD! Thank you so much bruh… Really thank you <3
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.