Using Photostory 2021...I'm trying to create a quick slideshow with about 700 pictures. I tried exporting it as 3840x2160 at 29.97 frames, and I get a pop up with an ! in the box, no text, and an ok button. Exporting as 1920x1200 works fine. The program doesn't crash or give any information with 4k. I'm running this on a windows 11 machines with gobs of CPU/memory/disk. (18 cores, 64gb memory, etc.).
I've done other slideshows at 4k with far fewer pictures (120ish) with no issues. Any ideas what may be happening here?