Cleo EDI Integrator has the command: RFRMC. We use it to refresh the Cleo/EXTOL mapping indices.
This command is primarily used when we encounter generation and/or translation error. We will see the errors message within the 'Inbound Application Data logs' or 'Outbound Application Data logs'
There are many reasons for this type of error but I have found when a certain map is being updated by one session and another session from the same user /different uses changes the same map, a lock is applied to the respective mapping records.

This lock will not be removed until RFRMC is executed.

Typical Error Messages:
Error loading message class segment table for MSG ID/class 850/ABC850
Error loading tables for message ID "869"; message class "ABC850".
Cause . . . . . : An internal error was detected while attempting to load
the message class segment map table for message ID 850 message class
ABC850. The reason code is 2 from the following list:
1 - The number of segments is above the maximum
2 - The index in the file does not match the sequentially generated index.


Recovery . . . : For reason 1, contact your program support representative.
For reason 2, refresh the file indices by updating the message class.


NOTE: Running RFRMC for ALL maps is not recommended. Running RFRMC over specific maps is preferred.