BFGSS0023E errors and how to avoid them

If you uninstall a Fix Pack from an installation in order to move back to a previous version of the product, and an agent associated with the installation was involved with managed transfers at the time the uninstallation took place, then that agent cannot start and will report an BFGSS0023E error. You can avoid this error by completing a number of steps that should prevent BFGSS0023E messages from appearing when the agents are restarted.

For every in-flight managed transfer that an agent is currently involved in, there is a message on the agent's SYSTEM.FTE.STATE.agent_name queue. This message stores checkpoint information on the managed transfer, and is used if the managed transfer goes into recovery. Once a managed transfer has finished, then the corresponding message on the SYSTEM.FTE.STATE.agent_name queue is removed.

Each state message contains some internal header information indicating which version of the Managed File Transfer component was being used by an agent when the managed transfer was running. The version information shows the specific Fix Pack level, so, for example, if an IBM® MQ 8.0.0 Fix Pack 5 agent was running a managed transfer, then the state message for that managed transfer would contain a reference to IBM MQ 8.0.0 Fix Pack 5.

If a Fix Pack is uninstalled from an installation, and an agent associated with that installation has in-flight transfers associated with it, then the agent fails to start and reports the following error:
BFGSS0023E: The agent is configured to use IBM MQ queues that contain data created using a later version 
of the product. The agent cannot run in this configuration and will end.

For example, if an IBM MQ 8.0.0 Fix Pack 5 agent has some in-flight transfers running when it is stopped and then downgraded to the IBM MQ 8.0.0 Fix Pack 4 level, the next time the agent is started, it checks the messages on its SYSTEM.FTE.STATE.agent_name queue and finds that they were written when it was using IBM MQ 8.0.0 Fix Pack 5. As it is now using IBM MQ 8.0.0 Fix Pack 4, the agent reports the BFGSS0023E error described in the previous paragraph and shuts itself down.

As a general rule, if you want to remove a Fix Pack to either the Managed File Transfer component completing the following steps should prevent the BFGSS0023E messages from appearing when the agents are restarted:
  1. Ensure that all of their agents have completed their managed transfers.
  2. Stop the agents.
  3. Remove the Fix Pack.
  4. Restart the agents.