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.
Wow, they’re really shitting the bed aren’t they?
It was always going to happen, and the best time to shit the bed, is when you’ve already wet yourself, because the sheets have to be changed anyway, right?