More than one group is being mapped to group <name>. Only one group can be merged with a group in the domain. Correct group <name> and try again.
When you upgrade groups in the repository, you are trying to map multiple groups in the selected domain to a single group in the PowerCenter® domain. For example, you cannot map groups “Sales” and “sales” in the selected domain to group “Sales” in the PowerCenter domain. In the PowerCenter domain, group names are not case sensitive.
Rename the group in the selected domain or merge one of the groups in the selected domain with a different group in the PowerCenter domain.