When a user tries to sign in to Microsoft Lync or Skype for Business in Office 365 Dedicated, the user receives one of the following error messages.
Error message for Communicator 2007 R2
Cannot sign in to Communicator because the sign-in address was not found. Please verify the sign-in address and try again. If the problem persists, contact your system administrator.
Error message for Lync 2010
Cannot sign in to Lync because the sign-in address was not found. Please verify the sign-in address and try again. If the problem persists, contact your system administrator.
Error message for Lync 2013 or Skype for Business
You didn’t get signed in. It might be your sign-in address or logon credentials, so try those again. If that doesn’t work, contact your support team.