You can’t view notifications in the app without enabling push notifications and email notifications now

This might be a server side error, actually. Here’s a comment from someone on r/redditmobile:

“For me, it displays the “no notifications” prompt. I think there is a server/app error that is causing notifications to not display. The “enable notifications and email” pop ups that occur when checking the activity screen might display instead of the “no notifications” box might appear if you do not have them enabled.”