can’t add new bone ‘root’ outside of edit mode, incorrect armature for type ‘ utils’

Hi,
I’m trying to create a rig with the riggify add-on. When I press generate this alert comes up: “can’t add new bone ‘root’ outside of edit mode, incorrect armature for type ‘ utils’”. I have two other rigs on the same model for the face and eyes.
How can I apply the generate rig to the metarig?
Thanks!

Add a link to your model. You can delete the meshes, we just need to see the armatures.

http://pasteall.org/blend/index.php?id=43714

There is an armature named “rig” on layer 14. Rename it to something else. Also make sure to apply the scale to the metarig before you generate it.

Thanks so much! I completely forgot I had that rig on the other layer.

Also, your meshes should not be parented to the metarig, and should not have any armature modifiers that point at the metarig.