iTunes won't download longer podcasts (Windows)

I'm having issues with downloading podcasts. Shorter podcast episodes (30 mins or less) don't seem to be a problem, but 45 min+ episodes suddenly can't download anymore. They appear in my podcasts with a ⚠ next to the episode, unable to play or download with no indication as to why. Restarting iTunes did nothing.

I've been switching episodes on my iPod all week, and this hasn't been an issue until today. It's like it came out of nowhere.