The server returned an unsupported content type. Was expecting 'application/rss+xml', 'text/xml', 'application/xml' or 'application/json' but received 'text/plain'.
I'm not familiar with AWS, but I would try changing the extension to ".json" and see if AWS serves it up with a Content-Type of "application/json".
“DGPT-ROKU-FEED.xml” has failed to upload. Sorry, this file type is not permitted for security reasons.
For MRSS feeds a video type must be provided.