I did a job this week using a set-up I've used many times before.

Main vMix machine for main mix and stream.

vMix on laptop with ALPHA output via NDI for additional overlay.

Tricaster advanced as hot backup.


When I went to send the laptop overlay to the main machine it wouldn't display at all.

After persevering with restarts of vMix, Tricaster and the PC's themselves I eventually got a weird mix of results.


The main machine could see all the Tricaster NDI channels but they were all black, sometimes the Tricaster could see the laptop properly, but then not at all. Then it would see the background colour but not the overlay. The Tricaster would sometimes see the main machine but not always

The main vMix machine refused to see the laptop at all, the laptop could see some of the Tricaster channels and the main machine but all the inputs were black.

All machines were on a dedicated network running through a D-Link gigaswitch with a 70mb internet connection. I've used the same set-up at the same location before with no issues.


Anyone got any thoughts?