This XML file does not appear to have any style information associated with it.

Chrome doesn’t have an rss reader built in. You need to add an extension that parses/styles feeds.

It doesn’t matter – it does this on Safari, too. And in Safari, it opens my RSS feed program on other sites, but not on this one, so something is wrong somehow. ??

The feed works fine. As I said, Chrome (and probably Safari) users will need an extension installed to view it in the browser and get the option to add it to their feed reader. Most people will just paste the feed url into their feed reader anyway.
So this is a browser issue, not a WP issue.

Why does it matter than your RSS feed is unstyled? The RSS feed is for computers and computers don’t care about styling.

If it is not a WordPress os site issue, then tell me why this site works and this one does not?

acadiaclinical.com – works on all three browsers
kotawcontentmarketing.com – only works in Firefox

??

Can you replicate this problem with all plugins disabled and using the default theme?

If it is not a WordPress os site issue, then tell me why this site works and this one does not?

They have different themes.

kotawcontentmarketing.com/feed works fine in IE, Chrome, and Safari.

What’s do you see as working between the two?
https://snag.gy/0dlVv.jpg
https://snag.gy/1ux1c.jpg

The behavior is the same for acadiaclinical.com and your site here. If I turn off the Chrome extension, I get the unstyled feed for acadiaclinical.com:
“This XML file does not appear to have any style information associated with it. The document tree is shown below. “
A feed url opens an xml file which by default isn’t styled. A reader (or browser plug in) is what makes it human readable.

acadiaclinical works in Safari for me though. What’s the difference? I’ll try turning off plugins and themes.

I don’t have Safari handy, but as long as you see the xml file, the feed is fine and the difference is a browser setting.