After the most recent update to adobe premiere pro anytime I scale down a 4k clip, the preview of the clip in the Program panel doesn't show anymore. It is just a black screen until I change it back to scale 100.
Any other clips / video I have that are in 1920x1080 resolution show just fine in the Program panel. If I leave the scale at 100 or higher for the 4k clips I can see the video but it isn't fit within the window/panel so editing is obviously harder to do.
I have changed the sequence settings to 4K resolution and then tested scaling the 4k clip down and the same thing occurs. I've even started an entire new project in premiere and same thing.
Edit: I have also found that if I export the entire sequence all of the scaled down 4k video doesn't display either. It's just black video with only audio.
Having the same issue, I have had to change a 4K creative to a 1:1 aspect ratio and that seems to have caused the problem. Premiere just doesn't like aspect ratio changing, even while they tout this auto reframe feature.