It happens to me too. I think it's The Economist's paywall in action. It's pretty annoying that this article is linkable but not-really on the web.
That's a broken paywall, then. I'm on mobile, so not using any ad blocker, but there was no hint of explanation.
I had the same thing happen, but it stayed open fine once I tried the link in incognito mode. Probably just a mis-coded "you've reached your article limit for the month" deal.
Same in Firefox for me.
I switched to "Reader View" (I love this feature) and the text appeared.