If after upgrading your server to the latest system software version (such as version 1.1.1) you need to go back to an older version (such as version 1.0.1 or 1.0) you must perform an additional AC power cycle of the server after the downgrade has completed to ensure proper system operation.
An AC power cycle can be performed by shutting down the system and removing the AC power cords from the power supplies. Then, plug the AC power cords back into the power supplies and restart the system.