If you've been running the iOS 12 betas, then you've probably been seeing a really annoying pop-up on your phone lately. Every time you unlock your iOS device, a message pops up that says, "A new iOS update is now available. Please update from the iOS 12 beta."
But alas, when checking for updates, there isn't one. There's no new update available, as was indicated by that persistent and annoying message.
But today, a fix is finally rolling out in the form of iOS 12 developer beta 12. Indeed, 12 betas for a single iOS update is unprecedented, but build 16A5366a was absolutely necessary. After all, we're not going to see the GM seed until September 12, when Apple is going to announce new iPhones. No one wants to live with that pop-up message until then.
This is more than likely going to be the last beta build before the GM seed, unless another show-stopping bug is found. Following the September 12 event, the general public should see the iOS 12 update after a couple of weeks.