Thanks. I've been getting some good advice on cleaners so wanted to send back a little thank-you.
I had the same issue in Firefox and Chrome. I opened a Firefox Private window (which has no cookies or cache) and was able to get to the page. Did a little poking around in the Firefox Developer window (F12) and something made me think, hmm, it works when I'm NOT logged in. And sure enough, when I logged out in my non-private window, I was able to get to the page. Then I logged in so it wouldn't create a new profile before letting me donate. So something is blocking logged-in users from getting to that page. In fact, when I'm logged in, I can't get to Pool School or Pool Math pages either--it just sends me back to /blog.