If you are having trouble getting Sunday Keys downloaded, you'll want to make sure you have a solid internet connection and that you aren't running other apps or programs while you download.
You'll want to leave Safari open while the download takes place and watch the download progress in the browser (rather than minimize Safari while it downloads). I’d also suggest using a different browser like Chrome if you have trouble with Safari.
Sunday Keys for MainStage and Ableton are both large files, so there is a longer period of time where if anything that goes wrong connection-wise that will impact the download.
Contact us if you are unable to get it downloaded to your computer after trying these things.