Vegas 19. Some catastrophic image corruption happened playing some stills in my project while I was adjusting the Range Limited Color Wheels. So I went into testing mode.

I reset Vegas first. Then I created an image with some color bands for my testing, but I think the same things will happen with any image or with a video event.

Here's my recipe if anyone would like to do a sanity check.

I made a simple project (HD-1080 30p, [ ] Adjust source media ... is checked) with my jpg (3840X2160) on the timeline twice together, 3 seconds duration each. Then made a loop across the two, and started playback with loop enabled. My objective was to have color grading on one copy and not the other. Watching playback in a loop shows behavior related to the color grading by contrasting the grade-effected event behavior with the non-effected one. So I selected the first event, and hit alt-G. Now the color grading panel appeared, and the first clip showed there's an effect, while on the 2nd clip there still isn't. Also the video scopes window appeared, docked. I selected histogram with luminance/R/G/B, and "update scopes while playing". Continued to keep the first event selected, so the wheels stayed lit up. Didn't change any color stuff.

Now watching (sometimes for a couple of passes of the loop):

1. The grey borders around the video scopes quiver slightly while playing the first event, but not the 2nd. Especially the right side.
2. Occasionally there is a brief distortion in the preview ("preview (full)" and others) and the histograms jump too, only when playing the first event, not the 2nd.
3. Alt-G closes the grading panel and closes the video scopes view. Now, no distortion in the preview.
4. I open the video scopes again (now not docked). Now I see occasional preview distortions again and the border of the video scope window is flickering, but only when playing event 1. Color grading panel still closed.
5. I try the "waveform" video scope view and all the same artifacts appear.
6. I click on the [FX] of event 1 and delete color grading. No more artifacts.
7. With event 1 still selected, alt-G opens color grading, assigns it to event 1, and docks video scopes. Artifacts happen again.
8. I close the docked video scope and playback is pristine.

Thinking about whether it is display hardware, I go to help->Check for Driver Updates. I see that my Intel UHD 630 is version 27.20.100.9316, but I see the three following lines show "not found".

Thinking further about hardware, if it were only the preview misbehaving I could be slightly suspicious of graphics h/w, but it sure seems like it is a weird interaction between color grading and the video scopes view.

Just for fun, here's the image I used for testing.

I haven't yet figured out the original problem I had, the catastrophic image corruption related to RL Color Wheels, unless it is just a different, more extreme form of the distortion in this testing.