I don’t think you’d want to use FMeatSaveGameArchive as a UPROPERTY. I think you linked to this tutorial in an earlier question which shows it being used with MemoryWriter:
http://runedegroot.com/saving-and-loading-actor-data-in-unreal-engine-4/#comments
Basically, you don’t want to have FMeatSaveGameArchive as a member variable of anything, you just use it as part of the serialization / deserialization process.