During migration, the folllowing warning is seen in the log file.
WARNING: [5061-24-383-00000000] Unable to add base message properties, message ID =
This warning indicates that the base message property "message ID" could not be written, due to not being available in the source environment or corruption on the message.
Typically the messages will still migrate to the target environment regardless of this warning, verify that the message did in fact migrate.
Run GWCHECK prior to migration to ensure that all message properties can be read, see this solution for guidance on GWCHECK.