That notification just means your product is using a Remote Product File URL, and your remote file server failed to respond when we contacted that URL to verify the remote file still matched the copy of that file we cached from a prior download, so we just went ahead and issued the buyer a download from our cached copy as usual. If you're sure you haven't changed the remote file lately, you can safely just disregard that notification. It appears your remote file URL for that product is also on Amazon S3, so most likely access to that remote file was affected by today's outage as well. Your Transaction Log shows we processed that order a couple days ago, and the last download attempt on that link was made just after 11am MST today, right around the time the elevated error rate started cropping up on Amazon S3.