openshift cannot create imagestreammappings in project, error message in private registry.

when I push to the registry, I get a 500 internal error message. Openshift registry logs are:

time="2017-03-01T07:46:47.970130059Z" level=error msg="response    
 completed with error" err.code=unknown err.detail="User                               
\"system:serviceaccount:default:registry\" cannot create  
  imagestreammappings in project \"default\"" err.message="unknown error" go.version=go1.7.4 
http.request.contenttype="application/vnd.docker.distribution.manifest.v1+
prettyjws"