Since it WAS creating a file, though Kindle Previewer keeps saying the conversion failed, I tried opening it in Calibre. THAT WORKED! Only problem is with the cover image. I had it properly selected in the EPUB export dialog box, but it didn't show up in Calibre. So I added it in Calibre, but when I export to MOBI from there, although it has a cover image in the file itself, that image does not show up as the thumbnail in my Kindle library. Anybody know a way to rectify that? EDIT: Turns out that's a friendly way Amazon has of forcing you to use their tools and sell on their platform. So I'm just going to cross my fingers that when the client actually uploads it to Amazon as usual, some magic will occur to make the thumbnail function properly.
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