Apple re-signs iOS 15.4 to fix Studio Display update issue | Cult of Mac

Apple re-signs iOS 15.4 to fix Studio Display update issue


Firmware updates for Studio Displays failed over the weekend but they're fixed now.
Firmware updates for Studio Displays failed over the weekend but they're fixed now.
Photo: Apple

Late last week, Apple stopped signing iOS 15.4 following the release of iOS 15.4.1, making it impossible for users to downgrade their iPhones’ software. But the change also inadvertently stopped people from updating their new Studio Displays’ firmware, based on iOS.

Complaints ensued on Sunday. And before the end of the day, Cupertino re-signed iOS 15.4, making it valid and verifiable to servers again.

Did Apple release the $1,599 Studio Display with so much fanfare only to forget about it when it launched iOS 15.4.1?

Apple quickly re-signs iOS 15.4 for Studio Displays, appearing to fix update verification problem

Apple released iOS and iPadOS 15.4.1 for iPhone and iPad users last month. But the Studio Display remains with its newest update, iOS 15.4. So it appears updates for the Studio Display are not tightly coordinated with iOS and iPadOS releases.

On Friday, Apple stopped signing iOS 15.4 just over a week after the release of 15.4.1. On Sunday, various sources reported that a growing number of Studio Display owners could not update their displays to iOS 15.4. Studio Displays run on iOS using an A13 Bionic chip.

Less than a day later, Apple fixed the issue involving being unable to verify software by re-signing iOS 15.4.

Previously, Apple has promised an update for the Studio Display to improve poor webcam quality. However, it offered no timeline for the update’s availability.

Perhaps many folks rushed to update the firmware hoping for the webcam fix, only to discover they couldn’t update at all. And then, once they could, after Apple re-signed iOS 15.4, the fix wasn’t there. It appears the webcam improvement is still to come.

Seems like a mistake

And Apple hasn’t commented on the reason the Studio Display firmware update failed or about its re-signing of iOS 15.4. But the idea that it goofed up is certainly making the rounds.

Among others, Macworld suggested Apple basically forgot the Studio Display exists when it rolled out iOS 15.4.1:

As it turns out, the root of the problem was Apple itself. On Friday, Apple stopped signing iOS 15.4 after it released iOS 15.4.1 on March 30. When Apple stops signing a version of an operating system, it becomes unavailable and devices can’t install it. Since the Studio Display basically has the guts of an iPhone 11, it couldn’t properly install version 15.4—and 15.4.1 isn’t available for Studio Display.




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