If a Calendar Server has configured separate LDAP directories for authentication and user preferences, you must run the Schema Migration Utility (commdirmig) against both directories.
To check if your Calendar Server deployment uses two different directories, examine the values for the following parameters in the Calendar Server configuration file, ics.conf:
local.authldapbasedn local.authldaphost
and
local.ugldapbasedn local.ugldaphost
If the basedn and host values for these parameters are different, Calendar Server is using two different LDAP directories.