I'm getting this error message:
RBAC authorization returns Access Denied for user ourdomain.local/Domain Controllers/servername. Reason: No role assignments associated with the specified user were found on Domain Controller servername.ourdomain.local
Event ID: 17, Source: MSExchange RBAC
I saw a similar posting for this type of error message but this one seems to reference some kind of system user account. So I don't think its any person trying to do something they do not have permissions for. This is a from Exchange Server 2010 running on Small Business Server 2011.