It's not often Apple says sorry.
The update, iOS 9.2.1, is the same version number currently available for iPhones, only the operating system has been altered to allow restoration of a bricked device and is available through iTunes on a Mac or PC computer.
Users who aren’t experiencing the issue or update using Apple’s over-the-air service do not need to update.
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There’s one caveat, however. After restoring a repaired device, the Touch ID sensor will remain disabled until repaired by an official Apple repair technician.
Error 53 occurred after an iPhone user had his or her device repaired by an unauthorized party. If the repair included replacing or tampering with the home button—where Apple’s Touch ID fingerprint sensor is found—the user’s device would stop working. Users were unable to restore the device using iTunes on a Mac or PC, with Apple requesting users impacted by the issue to contact support or visit an Apple retail store. Ultimately, the device couldn’t be repaired and had to be replaced.
Stirring controversy around the decision to disable repaired devices is that Apple gave no prior warning before implementing the apparently new policy with the release of iOS 9 in September 2015.
For more on Error 53, watch our video.
That meant users who previously had a device repaired were able to use it—albeit with a disabled Touch ID sensor, as was how Apple handled unauthorized repairs at the time—only to discover after updating to iOS 9, the device was rendered unusable.
Last week, a Seattle-based law firm filed a class-action lawsuit against Apple due to the practice.
Apple provided Fortune with the following statement, detailing the cause and offering possible refunds to those who’ve had to replace a device:
For more read Apple Hit With Lawsuit Over iPhone-Breaking Error
The Apple support page specific to this issue has been updated and now walks customers through restoring a device using iTunes and troubleshooting any further issues.
Apple is currently working on a fix for another issue that recently surfaced. The bug involves setting the date on an iOS device to January 1, 1970, which also renders the device unusable. Apple has acknowledged the issue and promised to fix it in an upcoming iOS update.