[NSFW] RSS Subscription Link Broken

I’m having trouble with my RSS feed subscription link. It’s a default part of my theme. I haven’t altered it at all (at least to my knowledge). However when I click the link, it takes me to the code for the subscription page, rather than an actual page, and gives me this message:

This XML file does not appear to have any style information associated with it. The document tree is shown below.

So I guess the information is all there, just the formatting information got lost somehow? It would be helpful if someone could please give me some advice on how to fix this. I’m a newb when it comes to webdev.

You can go see the problem for yourself at my site. Be careful as it is an adult site with potentially offensive material:
https://futanarifascination.com