Were you able to find a solution? I'm getting that same "JSON file for ... had no entries" error as well.

Were you able to find a fix? I'm finding a similar issue and am not sure what the problem is at all. Sometimes my AASA file gets downloaded and sometimes it doesn't, and this \u003c error is one of the ones thrown. I think maybe it's parsing the headers as part of the JSON? When I curl the file it successfully downloads, but I have header content like in @mtsibulski's answer. \u003c is Unicode for "", which is what shows up in the headers.