Hey,

vMix shows a very cryptic error message when something is wrong with my decklink card.
I assume this just is the error from the desktop video driver from blackmagic.

So far so good and understandable, but I'd suggest inserting an additional layer to check some conditions befor showing the driver error.

In my example the option "Start External Output" was enabled on my rental workstation and I tried to add a certain decklink sdi connector as an input.
I always got a very confusing error message, but after some trial and error it was just the external output having an external renderer enabled with the same decklink sdi connector selected as output.
So obviously you can't use the same sdi connector as an in- and output. So disabling the external output, external renderer or selecting a different connector would be easy fixes.

Maybe vMix could help with an info message before showing the decklink error message in case a connector is already used. This would help a lot to simplify or even prevent troubleshooting.

Thanks and kind regards
Jan