When adding a default search to a user role, you may see the message:
The combination of Role ID and Formlet Name is not unique for all Role default search: <search number> ...
This warning appears because there is already a default search assigned to this role for this object.
Only 1 default search is allowed per object (Asset, Contact, Company, Location, Legal Document, etc.)
The solution is to review the other default searches for this user role and object, and either:
1) Modify the existing default search for this object (and user role)
2) Remove the existing default search for this object from the user role, and add the new default search.