Immediately after installing Vegas 20 Edit, the bottom third to half of my desktop flickers quite annoyingly. I have a dual monitor setup and the flickering is only on the monitor using display port and not the one using HDMI. I
I'm running Windows 10 and never had a problem with version 13.
The minimum computer system requirements for Vegas Pro 13 and Vegas Pro 20 are significantly different. It would be worthwhile checking to make sure your computer and especially GPUs meet Vegas Pro 20's system requirements as per https://www.vegascreativesoftware.com/us/specifications/#productMenu. If they do, then that's a possibility that can most likely be eliminated.
I wanted to let you all know that it appears I have a bad display port cable. Turns out it was just a hardware issue and coincidental to upgrading to Vegas 20 when it decided to show itself. Thanks to all.
@Mark-Davidson6503 Thanks for coming forward to post the cause of the error. Often the errors are so trivial that we don't even dare think about them - but a great help to those who encounter a similar error.
That's how forums work - we learn from each other.