Strange bug I found in my project:
Vegas Pro 16 (checked 361/424) - hangs when I try to open NeatVideo4 window ("PrepareNoiseProfile" or "AdjustFilterSettings" button) if there is audio track on top of other tracks (screenshot #1). But if I move that audio track down (screenshot #2) - no any problems.
You can check it - here is the link to project file - you just need NeatVideo4 installed:
https://drive.google.com/open?id=1hngAbTRw_D6RJw7Sh8PuRieTcDFWvZeQ
Just open project, ignore all missing files, find "Black Solid" at the end of timeline, open it's "Media FX", and try to open NeatVideo4 window. Vegas will completely freeze.
Now restart Vegas, do steps again, but move top audio track down to other audio tracks - and viola - you can open NeatVideo4 window without any problems.
p.s. I know that I shouldn't add NeatVideo4 to Solids, but it is only for testing purpose - because I provide only project file without medias, which are required to open their "Media FX". That bug appears with any clip on timeline and go away after moving top audiotrack down.