Symptoms
If you set the AllowExchangeConnectivity attribute for the mobility policy to false in Microsoft Skype for Business Server 2015, Skype for Business on Mac clients can't retrieve meeting information through the Exchange Web Services (EWS) connection to the Exchange server.
Cause
This issue occurs because the Unified Communications Web API (UCWA) module in Skype for Business Front End server doesn't implement this feature.
Resolution
To fix this issue, install the December 2017 cumulative update 6.0.9319.510 for Skype for Business Server 2015, Web Components Server.
