I am trying to add a cover to a manuscript mobi ebook compile in Scrivener 3 for MacOS. I can import the image and the image is a cover option that I choose, but the compile in mobi format results in the generic ebook cover and not the image I’ve chosen. Help!
You’ll find all settings regarding the cover options documented in §23.4.5 of the user manual. They are located in the tab with an icon that looks like a picture of mountains, second from the right, in the compile overview screen. In your case you probably just need to choose the image your imported from the dropdown menu at the top of that pane.
Thanks Amber, I have done all that and followed the manual. I have eleven other novels in eleven other Scrivener files and when I compile them for .mobi, the cover shows in the Kindle library, just not in this file, so I am at a loss. I’ve even tried swapping out the image to see if that was the problem, but it’s not. My next step, I guess, is to recreate the file. 
Oh, if you’re using the Kindle reader program as a reference point that might be the problem. It isn’t really tuned for testing, more for end user reading, where caching a cover image in perpetuity is probably acceptable. If you’re switching cover images around or accidentally first imported with the placeholder, it can get stuck on that until you clear the cache. I’m not sure what the safest way is for doing that at this point in time.
But it might be easier to just use something else to make sure your settings are correct. Kindle Previewer doesn’t cache anything, and Calibre viewer should also work.
I think you’re right. When I display it in Caliber, I can see the cover. It just must be a Kindle app thing on my Mac
fyi - The issue is only with the compile made from this Scrivener file—the Kindle app just won’t display its cover, although it does display the covers of my other eleven novels. But when I bring this “coverless” .mobi into the Kindle app on another Mac, the cover shows up.
If the Kindle you are testing with segregates “Books” from “Docs”, then you might see that effect. KindleGen sets the ebook type to “Document” which causes it to be sorted in among .docx, .pdf and other files you’ve loaded to the device yourself.
Other programs that generate non-KindleGen output might do differently. You should inspect them to ensure they are producing output that is in line with KindleGen, which is tuned for KDP upload.