Hi, i know this is an old post but i've just come up with this problem, I can Selectively prerender sections in Video For Windows which is an AVI but not in (NVENC), I used to be able to tho, any length i wanted without having to disable Audio,

Now the MP4 icon appears while it's rendering as if it's doing it's thing but it instantly disappears when rendering has finished, in the past i had to click Clean Prerendered Videos, now it doesn't even create them, not wholly anyway.

It will Render As in the normal way tho with (NVENC). Did this get resolved for you people ? I've uninstalled then reinstalled Vegas, Windows update, reinstalled all Graphics drivers, Nvidia & Intel but no joy,🤷‍♂️

thanks.

(i forgot to turn off Open folder when Completed in this vid 🥴)