Possible FIX:
Okay.
This error can be caused by the fact that the code is not using the same declared tags when it comes to signaling on the server.
If in the signaling you declare the tag "playerControls" and later decide to change it, then you should check well that all the tags were updated to this new name.
Hi. Please about an error with the multiplayer plugin.
Why does this error happen? Any clues?