Issue: Unable to find or provision user for Lync.
Error: Get-CsUser : Login failed for user '……'
Problem Statement: whenever you to find user for Lync or provision user for Lync access you will see above error even if you have Domain Admin or enterprise admins group permission.
To get Lync specific information you must have Lync server group permission. Means Lync specific permission is must to perform Lync server or user specific work.
Log on to Windows Server, like domain controller etc. with Domain Admin account or elevated permission.
1. Open Active Directory and Computer.
2. Right click on Domain name and say ‘Find’
3. Type ‘RTCUniversalUserAdmins’ and click on Find
4. Once find the ‘RTCUniversalUserAdmins’, right click on it and click on properties > Member > Add > type user name who want to enroll or search Lync user object. And click Apply > OK
5. Now you login on Lync server and open ‘Lync Management Shell’ and find or enroll user for Lync.