This is a recurrent bug which has affected a number of people. 'PeculiarFinds' (https://discussions.apple.com/profile/PeculiarFinds) posted this possible solution though I don't know how effective it is likely to be:
- Download the itunes app
- Open itunes app
- Mouse over "Account" on the top menu bar
- Click on "sign in." If you are already signed in then sign out and click on the "sign in" to sign in again.
- It will take you to a login page. Log in.
- It will tell you something to the affect that you are a new user and aren't able to use all services yet or something like that
- Follow the step by step prompts. It will tell you something about a credit card but you don't have to enter one. Just fill out your name and address and continue through the prompts.
- It will tell you that you can now log into all of apple services
- Open the podcasts screen in the itunes app
- On the menu on the right click on "submit podcast"
- It will take you to a login screen. Log in
- It will ask you to accept terms of service. Accept it.
- It will now take you to the podcast connect and you can submit your podcast.l
- If it doesn't work then go into the itunes app, click on "account" again, and select "authorizations-->authorize this computer" and go through that process and then try all of these steps again.
https://discussions.apple.chttps://itunespartner.apple.com/en/podcasts/overview
If this fails I would suggest reporting it Podcasts Support. Go to https://itunespartner.apple.com/en/podcasts/overview and click the 'Contact Us' link at the bottom of the page.