Apple Stops Signing iOS 15.4 Following iOS 15.4.1 Release, Downgrading No Longer Possible
Following the March 31 release of iOS 15.4.1, Apple has stopped signing iOS 15.4, the previously available version of iOS that came out earlier in March. As iOS 15.4 is no longer being signed, it is not possible to downgrade to that version of iOS once you've installed iOS 15.4.1.

Apple routinely stops signing older versions of software updates after new releases come out in order to encourage customers to keep their operating systems up to date, so it is not unusual that iOS 15.4 is no longer being signed.
iOS 15.4 was a major update featuring support for unlocking an iPhone while wearing a mask, new emoji characters, Universal Control on the iPad, and tons more.
iOS 15.4.1 added a fix for a battery drain issue on the iPhone, but more importantly, it addressed AppleAVD issue that could allow an application to execute arbitrary code with kernel privileges. Apple said this exploit may have been actively exploited, so it is a good idea to update to iOS 15.4.1 if you have not done so already.
Apple has also stopped signing tvOS 15.4 and HomePod 15.4 software.
Popular Stories
Apple today shared an ad that shows how the upgraded Center Stage front camera on the latest iPhones improves the process of taking a group selfie.
"Watch how the new front facing camera on iPhone 17 Pro takes group selfies that automatically expand and rotate as more people come into frame," says Apple. While the ad is focused on the iPhone 17 Pro and iPhone 17 Pro Max, the regular iPhone...
In select U.S. states, residents can add their driver's license or state ID to the Apple Wallet app on the iPhone and Apple Watch, and then use it to display proof of identity or age at select airports and businesses, and in select apps.
The feature is currently available in 13 U.S. states and Puerto Rico, and it is expected to launch in at least seven more in the future.
To set up the...
Apple plans to announce the iPhone 17e on Thursday, February 19, according to Macwelt, the German equivalent of Macworld.
The report, citing industry sources, is available in English on Macworld.
Apple announced the iPhone 16e on Wednesday, February 19 last year, so the iPhone 17e would be unveiled exactly one year later if this rumor is accurate. It is quite uncommon for Apple to unveil...
In the iOS 26.4 update that's coming this spring, Apple will introduce a new version of Siri that's going to overhaul how we interact with the personal assistant and what it's able to do.
The iOS 26.4 version of Siri won't work like ChatGPT or Claude, but it will rely on large language models (LLMs) and has been updated from the ground up.
Upgraded Architecture
The next-generation...
New MacBook Pro models with the M5 Pro and M5 Max chips could arrive as soon as Monday, March 2, according to Bloomberg's Mark Gurman.
In today's "Power On" newsletter, Gurman said that the release of new MacBook Pro models is tied to the release of macOS Tahoe 26.3. The launch is said to be slated for as early as the week of March 2. He added that the M4 Pro and M4 Max models on sale today...