could you Login with the Admin user into ITSM >> Applications >> AR System Administration Console >> System >> General >> Server information
Now go to the "Configuration" tab and look for the check-box with label "Disable Admin Operations". Uncheck the check-box and restart the AR service.
Also check on on the Server ranking form for the primary server entries whether FQDN name is present or not ? if not then add an entry with primary server FQDN name and set admin ops to true
It has been soluced:
MIDTIER request information by searching based on ARS/CMDBserver name, but not on information of MIDTIER config.properties.
Actually, MIDTIER is configured to point on staged server for migration, not with an alias but with FQDN and MIDTIER call the alias fatally the wrong ARS server because call the alias of current QA server.
Effectively on current used QA ARS server, administration is enabled on the other server then it shout that admin mode is not enabled on the server.