When you start a video call in the Skype for Business 2016 client in a VDIv2 environment, you may find remote desktop protocol (RDP) is always used for screen sharing.
Note: This issue occurs when Video based Screen Sharing (VBSS) is enabled in Microsoft Skype for Business Server 2015.
This issue is caused by the following two problems:
The Skype for Business client creates a "screen scraper" media device for VBSS with local media platform, but in a Virtual Desktop Infrastructure (VDI) environment, the Skype for Business client will try to load a media device from remote media platform, which doesn't contain the "screen scraper" device.
In a VDI environment when the Skype for Business client tries to attach a media device to a media channel, it will try to load the media device from remote media platform. However, the "screen scraper" media device is in local media platform. Therefore, the Skype for Business client won't attach the media device to media channel.
To fix this issue, install the January 2, 2018, update (KB4011623) for Skype for Business 2016.