Symptoms
- Some users are not able to sign in to Skype for Business
AND
- Registration Method is set to "Automatic Registration"
AND
- The following appear in the Lync_Access_Control log: "User retreived retrieved from DB: \, based on SIP"
AND
- LAC filter version is lower than 2.7.1.0
Solution
Upgrade the Lync_Access_Control.dll to version 2.7.1.0 or greater