У вашего броузера проблема в совместимости с HTML5
You should be follow on 3 main steps bellow:
1. Generate Vray key using fx-vray125 app then export .key file
2. Copy files by following in video (source files from your folder location and target is from Applications folder on Mac OS) - quick tip: "command + C" to copy selected file/folder.
3. Final run Vray app to test and enjoy.
This tutorial I made on MacBook pro with Mojave OS and using Cinema 4D R19.
If this video run so fast, you could pause and do it than continue the video to cover and complete your tasks.