"RSS Feed Error - Invalid Feed format - Could not parse RSS Feed. Please check your RSS Feed."
This indicates that your RSS Feed does not respect the standards of RSS feed formatting or that you do not use a supported RSS or Atom Version (RSS 1.0 or above, Atom 1.0 or above).
Please don't go bang your head on the wall just yet...
We've got a few tools that could help you figure out what's wrong and help you fix it- see the feed specifications article of our community
Examples of Digesto email layout
Customizing email layout
How can I Include the full article in my Digesto Email?