@Gammafan Do we need to allow incoming traffic from port 5556 and 5558 to the machine we are running Video Stream on?
i.e port forwarding to that internal IP-address?

I am also suffering this issue.

I am using:
OS X El Capitan 10.11.5
Google Chrome: 50.0.2661.102 (64-bit)
Google Cast: 15.1120.0.4
Video Stream: 2.16.603.0

I am not sure if this happened because I updated OSX, Google Chrome or because I changed my router, they all kind of happened simultaneously.
Would appreciate if anyone could point me in the right direction.

/Rich