Gameobject save issue

[Elowy]

Describe the bug
When I try to edit and save a gameobject this error message is keeps popping up:

"The given key 'World.gameobject_template_addon' was not present in the dictionary."

I've tried to add a new file to the definitions:
"...\DbDefinitions\azeroth\gameobject_template_addon_ac.json"

It doesn't work.

Version: build 2961

Expected to save the gameobject modifications to the database.

I'm still trying to solve this issue, if I managed to fix it I will update this thread.