After adjusting some things, I got the plugin to work and I now know what the problem was!
I use VNC-viewer to remotely control the pc where the Vizard script is running on. When I closed the VNC-viewer after activating the Vizard script, the problem was solved. I also adjusted the stream rate from 60.00 to 30.00. I don't know if that matters anything. Nevertheless, the problem is solved
!