This often happens when there's a network fault between your ISP and Hulu.
We recommend that you try the following steps;
1. Retry the episode again. If the network has stabilised, you should be able to play the episode right away.
2. Try a different show or episode to see if the problem persists.
3. Quit the Hulu application and close it, then try it again.
Please give these steps a try and let us know if you need any further assistance.