**System Information**
Operating system: Windows
Graphics card: Designer graphics card
**Blender Version**
Broken: 3.0
**Short description of error**
I installed an add-on (it appeared in the files), but I couldn't turn it on because the Blender didn't see it.
**Exact steps for others to reproduce the error**
Install add-on named Mixer (link: [[ https://www.youtube.com/redirect?event=video_description&redir_token=QUFFLUhqbDJhMWVGaWVXdGtMeWhhZjhWZTR4YlBHTzJXd3xBQ3Jtc0trN0RmVmxMeS1mSFkwZGVyYm04cVRleTFiOGtDSmIxQlVwS1FuZVk0c1NNSU5rd1FucHd2MUZxZU5HVUF5dDdnal8zQmNiRjY3TXFNemlwdk5DZGhkV0lnUGYtS3dXUEtWa3JTOGh4SDZvQUtKS2Z0dw&q=https%3A%2F%2Fgitlab.com%2Fubisoft-animation-studio%2Fmixer&v=EvwSxwCjHUo | name ]]). Try to turn on it.