Hello Jimmy,
you can ignore this
it is just telling that the Entity MIB has set (armed) an alarm as a consequence of the event se2/1 link down
also error message decoder says:
1. %ENTITY_ALARM-6-INFO: [chars] [chars] [chars] [chars] [chars]
Alarm assertion or deassertion information.
Recommended Action: >> No action is required.
You may be more interested in investigating the up/downs of ser2/1 (if any)
Hope to help
Giuseppe