Download stopped partway through unable to restart

Yesterday I was downloading an HD film. I started watching it when 76% of it was downloaded. However, the system never downloaded the complete film. After 15 hours of waiting, I deleted the recording from my DVR and tried to download it again. But now it won't download anything.

My home internet connection is working fine and no errors are indicated in the system setup. I have run a system test and everything should be working fine. The top four green lights on the router are lit. 

I have an HR24/500 receiver.

I haven't made any changes to my home wifi setup.