I believe this just got introduced with the update from today.
When using a StarterCharacter with the default character sound files (died, swimming, etc) stored in the head, the following error occurs:
14:42:04.936 - Remote event invocation queue exhausted for Workspace.MapleMarvel.Head.FreeFalling.CharacterSoundEvent; did you forget to implement OnServerEvent? (x111)
To Reproduce. See attached file which has a StarterCharacter with the character sound files already stored in the head. Hit play in Studio, and wait about 2 minutes. You will see the errors in the output window.
Pretty sure that is going away soon. The whole Sound script that is. The new one can be found in this thread if you want to update it early or read up on it. Sound script changes