There's a general blueprint for improving error messages in general, see https://blueprints.launchpad.net/horizon/+spec/improve-error-message-details-for-usability .
In this case I think the administrator should also update OPENSTACK_IMAGE_BACKEND in the local settings in order to keep the list accurate, see http://docs.openstack.org/developer/horizon/topics/settings.html#openstack-image-backend (we can't get the list directly from Glance so it needs to be updated manually).
There's a general blueprint for improving error messages in general, see https:/ /blueprints. launchpad. net/horizon/ +spec/improve- error-message- details- for-usability .
In this case I think the administrator should also update OPENSTACK_ IMAGE_BACKEND in the local settings in order to keep the list accurate, see http:// docs.openstack. org/developer/ horizon/ topics/ settings. html#openstack- image-backend (we can't get the list directly from Glance so it needs to be updated manually).