The AX-3.7u1 release contains security enhancements which affect how a subordinate station 'Joins' with the Supervisor station. Specifically, a new slot has been added to the JoinProfile, the “Default Subordinate User Password” slot, which is used by the Supervisor during an initial Join with a Subordinate station. After upgrading, failure to update this slot's password information for the selected user will cause authentication errors if a Join is issued from the Subordinate station and that station does not already exist in the Supervisor's NiagaraNetwork (the Supervisor is not “aware” of this Subordinate).