This isn't anything remotely resembling a feed. its contents read
<Error>
<Code>NoSuchKey</Code>
<Message>The specified key does not exist.</Message>
<Key>feed.xml</Key>
<RequestId>*********************</RequestId>
<HostId>
********************************
</HostId>
</Error>
(I've blanked out the IDs to be on the safe side). The URL of your file is
https://s3.ca-central-1.amazonaws.com/thirdrssfee/feed.xml
I don't know what is going on here. Perhaps you've placed the feed on AWS but have failed to make it public. In any event, I have my doubts that using Amazon as a hosting service for podcasting is a practicable idea. But in any case you need to start by making your feed publicly available, if not on Amazon then somewhere else. Once you've done that, if you post it again if you like, and we can look at it and see whether it has any problems.