Recently I was giving a demo about Lync. When I went to the Calendar tab within Outlook I noticed that the “New Lync Meeting” button was missing.
After looking into a lot of settings I found out that it’s simply an add-in that was not loaded. Outlook disables add-ins that are decreasing performance. When you press the “Always enable this add-in” button under Lync Meeting Add-in for Microsoft Office 2013 it will always load the add-in.