The rss feed for the Bug category as a link doesn’t work on initial click:
https://meta.discourse.org/c/bug.rss
When linked from a post, it looks like the page is sticking around and returning a “Oops! That page doesn’t exist or is private.”
But a refresh of the page then loads the .rss/.json as expected?
That’s because the routes aren’t defined in the Ember side of the application.
It’s not really a problem for me personally, but I did find the behavior un-intuitive. It leaves the impression that the link is broken, when in fact it works just fine (especially in the ways that people who are looking for those links would use them - rss and json are hardly something you want to read in the browser I’d imagine 
).
This is a duplicate of several other bugs – Ember won’t route what it does not know about.