I came across a user not being able to sign in to the Lync 2010 client when Lync 2010 server was deployed in a resource forest.
The user was getting the normal error message.
Cannot sign in to Lync. You may have entered your sign-in address, user name, or password incorrectly. If your sign-in information is correct and the problem persists, please contact your system administrator.
Since the error message pointed to login credentials, I verified the following.
- I reset the user password to be sure.
- Account was not locked out.
- I could sign in from the user machine, which confirms that it is not a machine issue.
The problem was that a required attribute was not set for the user. When Lync 2010 is deployed in a resource forest along with Exchange, the MSRTCSIP-OriginatorSID attribute should match the msExchMasterAccountSid. In this user’s case, the attribute was not set (blank).
Once I set the attribute using ADSIEdit, the user was able to sign in straightaway.