5.4.0b7 Unexpected MonoBehaviour being transferred

I get this error on loading a scene:

Unexpected MonoBehaviour being transferred. Expecting transfer of MonoBehaviour ‘ComponentLibrary’, but MonoBehaviour being transferred is ‘(null)’

Its a bit cryptic so what does it actually mean?

I get this too in 5.4.0b9

I get something like this too. No progress on solving it?

Bug report please? And share the number after once you receive it.

Project too big. If you could give us a hint as to what that error means and why it might show up, maybe someone could narrow the problem down to a small repro project.

Looks related to the issue I posted: Unexpected recursive transfer of MonoBehaviour. - Unity Engine - Unity Discussions

The error is harmless and can be ignored. We have a fix in b9 or b10.