Same problem here. Everything is working in PIE, but when packaging, this error:
“UnregisterComponent: (/Engine/Transient.CharacterMovementComponent_0) Not registered. Aborting.” shows up several times and for example, “orient rotation to movement” in Defaults tab probably resets, because player is not rotating anymore.
Basic setup here, “Person” class derived from Character, and then “Player” class derived from “Person”. Using 4.6.1, pure blueprint project.
Edit: Looks like it generates this error when i change any property in Defaults tab of “Person” (child of Character) blueprint. So, for example, when i change “Orient Rotation to Movement” to true, it resets its value after packaging.
Edit2: When i reset all Defaults properties to default in Person class, and change them in children, these errors still show up, but now it’s working ok after packaging - player is rotating, so seems like this Orient Rotation to Movement was not reset this time. Strange.
Edit3: After restarting editor, packaging no longer shows these errors. More info in answer.