Apple apparently considers the rollout of iOS 9.3.1 a success, as the company has stopped signing code for iOS 9.2.1. This prevents users from downgrading their devices to the older version of the operating system.
Apple routinely ceases code signing on deemed obsolete iterations of iOS in order to ensure a consistent user experience and to protect consumers against bugs or security vulnerabilities fixed with the most recent software.
The iOS 9.3.1 release hasn’t been all smooth sailing for Apple and its users, as last week, Apple was forced to patch a bug that caused some apps to freeze or crash when the user clicked on a web link. It turned out that some apps, such as popular travel app Booking.com, contained a bloated associations file, which caused a data overflow that crashed such apps as Safari, Mail, and Messages.
In addition to that bug, iOS 9.3 as a whole has seen its share of issues, such as an Activation Lock bug with older devices that rendered them unusable. Apple pulled the update for those devices, and then issued a fix last week.
This week, iPhone 6s and iPhone 6s Plus users were afflicted with a bug which opened a security hole, in which a bad guy could have gotten access to contact information and a user’s photos without unlocking an iPhone. The bug used a combination of Siri, 3D Touch, and a combination of system settings to allow access. Although most considered the bug’s danger to the general install base of users as minimal, Apple fixed the bug on Tuesday.