Note: depending on how it is triggered, it still functions properly when the world is loaded in again after getting the error. This is an issue mainly for addon developers that try to create entities that have a player's nametag without scripting.

An addon has been provided with a custom entity that does the following:

Upon spawning, it will trigger the event that adds a new component group in the player.json that causes the player to transform into a pig, see error

When giving the player the "transformation" component (preferably through triggering an event that adds a component group) it sends the player to the main menu with the following error: