The csmig dry run mapping file and output file indicate that there is a duplicate calendar name.
For example, in the original database, jsmith owns the following calendars:
basketball with 5 events
jsmith:basketball with 10 events
The dry run indicates that during a migration, the two calendars will be merged, and the resulting calendar will be jsmith:basketball with owner jsmith and 15 total events
The output file will include the following warning message:
Error modifying calendar properties, error=2