RSS Errors change dlvr.it feed to inactive

Cannot get my dlvr.it account to stay active when pulling https://dodgecountyfairgrounds.com/feed

After 15 minutes it switches back to inactive, sends an email that my feed has been disabled till feed errors can be addressed. They recommend using the tool at W3C to diagnose but I need help interpreting the code https://validator.w3.org/feed/check.cgi?url=http%3A%2F%2Fdodgecountyfairgrounds.com%2Ffeed

Anyone else have this issue? What was the solution?

Thank you!
Dale