Hi,

The most common cause of black video on NDI sources, there are a couple of potential causes:

1. Firewall software.
This is quite common with anti virus and security software that has its own firewall.
If you have software like this installed on the computer you wish to capture, check its settings to allow vMix Desktop Capture.

2. Multiple subnets on the network
This is less common but means the computer in question may have multiple networks configured, either dual ethernet and wifi at the same time
or multiple IP addresses setup. Make sure only a single connection type is used and only a single IP address is configured on the source computer.

3. vMix Desktop Capture version might be out of date, download the latest from vmix.com/ndi and also make sure vMix is up to date.

Hope this helps.

Regards,

Martin
vMix