[RALLY 4.1.0] Verifier reconfigure fails when in "no admin" mode

Hi All, I'm using a Rally (4.1.0) deployment with existing users and no admin credentials. So the command "rally env show" outputs "admin": null in the json and it's ok. But the problem is that the command "rally verify configure-verifier -reconfigure" fails with: "rally_openstack.common.credential.OpenStackCredential() argument after ** must be a mapping, not NoneType" I've been struggling with this error for a number of hours with no results :-( Any idea ? I looked for a known bug in launchpad but found nothing. Thanks, Jean-Francois