This issue occurs to the accounts that are migrated from an on-premises deployment to Microsoft Lync Online.
Note Lync 2013 was upgraded to Skype for Business in April 2015.
To fix this issue, install the July 5, 2016, update (KB3115261) for Lync 2013 (Skype for Business).
Note Lync 2013 was upgraded to Skype for Business in April 2015.