Thank you for the clarification. Unity serialization is still a mystery to me so when I read the NodeCanvas documentation that “All the variables of a blackboard are able to save and load” I didn’t connect the dots that Unity Object references would not be possible. (Maybe a one-line note on the Blackboard Save & Load documentation page would be helpful to a future newbie like me?)
Yes, I am looking to save variables/state between game sessions, and rather than store a vector I wanted to store a game object reference (i.e. a checkpoint) in case I move the checkpoint during prototyping or even game play between sessions.
I’m not sure if it’s the most elegant solution, or the most performant, but for now I have attached a component to each check point game object that has a persistent GUID, and store a reference to that GUID in the blackboard as a string. On game start, I load the blackboard/saved GUID, find the game object based on that GUID, and use the game object reference from there.