It’s pulling them from a NAS network drive, and I copied them over to the computer itself, and it found them all. This was the worst instance of it skipping images, but it always seems to skip random ones here and there. We introduced this network drive mid-autumn, but the program seemed to be doing it even before that.
1) It just skipped them entirely.
2) Didn’t open at all.
Running on a Mac, if that matters.