TV show won't play because Quicktime doesn't work with iTunes version

I downloaded episode 1 of Mad Men. When I try to play it I get this error: This movie requires QuickTime, which is not supported by this version of iTunes

I read some of the other support discussions and tried to do 2 things:

(1) I tried to set iTunes to open in 32 bit mode. But, when I open iTunes after doing so, I get an error that iTunes must be opened in 64 bit mode. So, that didn't work.

(2) I tried to remove the movie, but instead of being asked whether I still wanted to keep it, it just asked me if I wanted to "hide" the movie. So, I'm not sure what this means.

How can I watch the show I downloaded? And, please provide really explicit instructions because I can't seem to follow the complicated directions some of the super smart people leave on these discussion groups.

I have a Macbook Pro 15 inch retina screen computer running Yosemite 10.10.3. I have iTunes 12.1.2.27.

Thanks,

Cameron