InDesign crashed each time I tried to convert my cover to an Alternate Layout, despite trying numerous variations of Liquid Layout including turning it off (whichI thought was the problem). When I tried an inside page, however, all worked fine.
Then I wondered whether it was because I had placed a video on the cover, which in fact really was an Image Sequence of about 500 jpegs. I had wondered whether it was because the page contains EPSes, but I suspect its the Image Sequence. Any solutions greatly appreciated.