Since updating premier to the latest version, my videos have been exporting really contrasty with crushed blacks. I've updated my video drivers and no luck. I've also tried re-installing premier, no luck there either.
I can export an .mpeg without problems, so I attached a gif showing the difference between mpeg and mp4 (part of the image is blacked out because I can't show it)
I'm revisiting this post because I'm still having the issue with hardware accelerated rendering. I even have a new computer and GPU but still get crushed blacks when exporting mp4s with GPU. I'd like the benefits of a faster GPU export, but can't as long as this problem persists.