[1.2.0-pre.6] The ghost collection contains a ghost which does not have a valid prefab on the client

Not sure why suddenly I get this error at windows client build. Any idea why get this error?

The ghost collection contains a ghost which does not have a valid prefab on the client! Ghost: ‘’ (‘ENTITY_NOT_FOUND’).

you don’t have all ghosts the server loaded when you set the connection as “in game” (the sub-scene was loaded yet) or the prefab itself has been destroyed.

Either you mark that prefab as Loading or ensure the sub-scene data you need are loaded before telling the server you are ready for receiving ghosts.