Assume that you try to call an Outlook contact by searching the contact in Microsoft Skype for Business. When you right-click the contact object and then select the Call option, the contact's phone number isn't displayed. This issue occurs intermittently.
To fix this issue, install the June 7, 2016, update (KB3115033) for Lync 2013 (Skype for Business).
Note Lync 2013 was upgraded to Skype for Business in April 2015.