As quoted from the linked post.
It looks like you’re part of one of our experiments. The logged-in mobile web experience is currently unavailable for a portion of users. To access the site you can log on via desktop, the mobile apps, or wait for the experiment to conclude.
This is separate from the API issue. This will actually BLOCK you from even viewing reddit on your phone without using the official app.
Archive.org link in case the post is removed.
Quora, basically.
I don’t think I’ve ever successfully read one of those, because Google brings me to the site and then it demands I log in. They even go so far as to blur all the content. It’s really really stupid.