Troubleshooting Client Connectivity Issues
The first step is to enable full logging in the Skype Client itself and then check the log on the client side. In Windows this normally means going to the Skype client "settings" and then "Enable Full Logging".
The defaults in Windows 2016 server leave clients crippled so they can't even download basic files or software. But Group Policy Management Editor comes to our rescue!
Use cmd or Powershell and run:
Choose your domain/computer and then navigate like below and create a new menu entry for IE11 or whatever your version is. Don't be worried if the highest version is IE10 it means that it applies to IE10 AND above.........