Premiere Elements 15 and 18 hang when using Pan and Zoom

When I try to pan a photo to get the Ken Burns effect the preview works fine but when I click on Done I get the spinning beach ball, and I have to force quit. The computer is a new 27" iMac with 24GB of RAM. This first happened with version 15 (but not on my MacBook with 14). I downloaded a trial version of 18 and the same thing happens. Any ideas?