Two issues have cropped up:

Mac OS 10.13.4 build 17e160e

Move a large number of images (10K) to a new folder shuts the app down but the images are moved

Again same thing with a different set of images (6K) only copy is available, the move command is greyed out, so I copied and again the app quit. Why is move not available?

Images are a mix of jpeg, pdf, mov, avi.