What can I do if a "downloading error has occured?"

Hi!

I rented a movie on my apple tv2 about two weeks ago. After waiting for 3 days for it to download, i finally sat down to watch it tonight. However, it says "An error occurred loading this content...try again later." I've tried it several times since and it won't work. What do I do? Also, is there an option to just watch it on my macbook pro? If so, where do i find it?
!

Thank you