This was seen in Beryllium SR1

The call that I sent (which is a modified OpenStack call) and the resulting error are in attachment.

The request that OpenStack sent contained the string "admin" in some of the tenant_id fields. ODL was throwing errors because "admin" wasn't matching its tenant_id regexp, so I tried to workaround this by manually replacing it with correct tenant_id and sending that, resulting in the NullPointerException.