I see we're already working with you on this via email, so we can continue our discussion there if need be.
In case anyone else happens across this in the future, that error is coming from Amazon S3, which we use for long-term storage and delivery of downloads. Sometimes this can be a rare sporadic error that arises and clears up by itself, especially if the file had been downloading successfully prior. However, since this is happening for a new upload, and issuing new links to test for that file still produced the same error for us, it seems there may have been some glitch in uploading the file or syncing it to our provisions on S3, so reuploading the file should resolve that.
