When attempting to apply a crop to images using copy/paste an error dialogue is presented which isn't very clear or helpful containing the phrase:
"An internal error has occurred: ?:0: attempt to perform arithmetic on a nil value"
A more useful error message could instead be presented so that (such as in my case) the user is aware that they are attempting to apply a crop to a video file (which isn't possible in Lightroom) and therefore the entire operation will fail until the video file is removed from the selection. In addition to this when I was attempting to troubleshoot the problem the video file in question did not appear as a video file (when using a filter to view just video files in the selection - no video files were found - instead only an 'unknown' file which caused the problem).
A video showing me recreate the issue before I discovered the solution is here: