Are you trying to reference a scene object from a prefab by any chance?
Prefabs can't reference scene objects in Unity - it looks like they can while you edit, but it won't save/load.
If this is the problem, one approach is to find the scene object at runtime (by name, tag etc.) and store it in a GameObject variable, then use that variable in actions.
If this isn't the problem, when is the connection lost?
