Lync User Has Video Enabled but The Video Option is Missing From Lync Client

I have seen in some cases that after enabling the correct telephony policy that users still do not have the “Video” button within the menu of the Lync client’s IM window. This is usually caused by a GPO of some sort not allowing the proper registry values to be updated. As always, I implore you to attempt restarting the Lync client before making the following change to see if the issue resolves itself and proceed at your own risk as we will be modifying the registry.

1. From the registry navigate to HKCU\Software\Microsoft\Communicator
2. Double click the OCTelephonyMode DWORD.
3. Change the Hexadecimal value to 1. 
4. Restart Lync

In most cases you will see the the value was set to 5, which is IM and Presense Only. 

I hope this helps.