Usually one of two causes: 1. A temp brake in the path to the files or 2. you're behind in listening. If you click on the exclamation point, a little dialog box will pop up and tell you which it is. If it's the latter, you will have the option to click a button and tell it to keep downloading episodes. If it's the former, it will usually get fixed quickly.

 

- "When I get a little money I buy books. If any is left over, I buy food and clothes." - Erasmus