Cannot add local user present in SP server to SP group via UserGroup web service

Question

I am trying to add user(s) to an existing group via the function AddUserCollectionToGroup() of webservice "Users and Groups" (Web Reference: http:///_vti_bin/usergroup.asmx).

I call this webservice to add a user who is 'Local Administrator of SharePoint server' to a group and get SoapServerException with inner exception message as 'The user does not exist or is not unique'. But when I check for the users present in the site collection level, this user does exist.

When I try to add other user, say farm admin which is in AD, then it is successfully added.

Am I missing something? Any help would be appreciated.

(I am using Sharepoint Enterprise)

Thanks and Regards

Arjabh

Answer 1

The below link solved my problem:

http://littletalk.wordpress.com/2009/12/14/the-user-does-not-exist-or-is-not-unique/