Because Apple hasn’t supported Aperture for several years, we have decided to stop supporting our Aperture plugin. If you have it and it works, you can still place orders with it. You can also design your pages in Aperture, export them (they’ll need to be individual 300 dpi, sRGB JPG files) and upload them to a project in your Couture Book account.
You may also want to consider switching to a different design and layout tool. We recommend Fundy (fundydesigner.com) and SmartAlbums (pixellu.com). Both are easy to use, have our sizes built in, and offer free trials.