Face bone won't delete in rigify


I’ve been trying to figure this out , but I’m stumped, I must be missing something.
I’m using Rigify.
It seems face bone is a problem, I deleted the face bones. Generation has thrown an exception … key ‘ORG-nose’ not found.
When I delete the bone in edit mode, I get the same problem and find the face bone has re-apeared.
How do I get rid of it permanently, so I can generate a rig?

Thanks for your help.