Rename theme - Footer has disappeared

I renamed a theme and set changed the name in /user/config/system.yaml
Everything is working fine but the content within the Footer has gone.
Can anyone help me to fix it?

I'm using big-picture skeleton

In the admin the theme has disappeared under "themes"

Did you also change the corresponding class name in the theme main PHP file?

Also, the main yaml file and blueprint

It's working now. Thank you!