@pigglypots I have been getting this error as well.
Have emailed Michael about it and he recommended although it did not work for me.
If not please make sure you close your issues that you don't need any more.The core cause is the globally unique identifier (GUID) in every item/episode of an RSS feed. Your written i Tunes reviews encourage me and they help other people find the podcast.If that GUID changes, RSS clients and podcast apps will think that is a new post. If you appreciate the podcasting information I share, please write your own review on i Tunes or Stitcher!Try burning your feed in Feedburner (https://feedburner.google.com/) to cleanse it then put the Feedburner feed into the Stack and try that Should work!well I am also suffering the loss of all my RSS News Feeds with RSS Factory.