When trying to launch Mediasite Mosaic on a Windows 10 device, I am receiving an error message, "Unable to access video library."

You will need to allow Mediasite Mosaic to access your video libraries.  To do so, Click the Windows Start Button > open Settings > Privacy, and scroll down in the left menu to App permissions > Videos.  There, you should configure your access settings as follows:

Tags: MyMediasite, Mosaic