If you double-click an image so that it is displayed as the current
image in the lower window pane, then select several thumbnails and then
choose the Crop command (New image menu), you are prompted with this
question:
You have selected a group of thumbnail images. Do you want to
apply this command to the selected thumbnails?
Yes: Apply command to the selected
thumbnails.
No: Apply command to the current image
Cancel: Cancel the command
Clicking the "Yes" button produces an abnormal termination of the
program.
The Crop command should not prompt with this question because it can be
applied only to a single image.