Vmix would crash randomly if I had NDI sources in the preset. Task Manager would show that it was still technically running, but the window would disappear and there were no errors in event monitor that coincided with the crashes. It took awhile after adding different inputs to track down that it was in fact NDI sources that were causing the crash. Using the new FEIM feature didn't help, Vmix still crashed. VMix support told me that the log was registering some sort of vague and rare hardware error. So, I updated my chipset driver, checked for BIOS updates, updated my USB drivers, tested my ram, tested my gpu, etc. Nothing helped or provided clues. So I reinstalled Windows and updated everything again with a fresh start. Nothing helped.

I had done some tests and found that NDI sources were also crashing OBS. So, clearly not a VMix problem, but I asked for advice from support anyhow. They said that NDI was resource heavy and that maybe my motherboard was bad, or my ram, my cpu, etc. I didn't want to believe this as the things I have thrown at this PC in the past have been comparable/ more extraneous to my current task and I hadn't any issues before.

The show was approaching, so I re-built the preset not using NDI. Lot of time, not as smooth, but everything worked. Went into rehearsal and found that Mix C that I was routing out of Vmix, into my Behringer X-32, and into an OBS.Ninja room that I was using as a greenroom would randomly stop sending any audio. Vmix didn't crash, it just stopped sending any audio to the board through that mix.

I had an older driver for my X-32 (X-USB) loaded because the newer ones do not allow any more than one stereo WDM channel, which I had been using to route some programs into the board through for past shows. I updated the driver, switched to ASIO drivers and the mix dropout problem went away. After the show, I did some stress tests and found that NDI inputs didn't crash VMix anymore either.

Hope this helps someone else.

AMD Ryzen Threadripper 2950x
MEG X399 Creation
NVidia GeForce RTX 2080 Ti