Apple has apologised to users whose phones were left disabled after they sought repairs from third-party providers.
Some iPhone owners took their smartphones to non-Apple technicians to be fixed when they needed a replacement for their home button.
After services were carried out, these individuals reported they received an 'error 53' message when they opened iTunes – and this software issue then effectively rendered the entire device unusable.
When a non-Apple repairer replaced the home button on an iPhone or iPad that had been damaged, a subsequent iOS update was then able to pick up on the presence of a non-standard component, before shutting down the device completely.
The issue is related to Apple's Touch ID reader, which is a part of the home button and is used to unlock the device by the user's fingerprint, instead of a conventional passcode.
When the error 53 issue was initially reported, Apple defended the measure as a security feature to protect customers.
It claimed it was intended to prevent a fraudulent Touch ID sensor from being used and urged any affected customers to contact Apple Support for further assistance.
However, the issue is now being described as a factory test and a fix is being distributed with iOS 9.2.1. Apple apologised for the inconvenience and offered reimbursement to those who paid for an out-of-warranty replacement of their device.
Ben Wood of CCS Insight said: “To me, there was a lot of logic in what they said around the 'error 53' element.
“If you're using your fingerprint to unlock sensitive data or make payments and there was the ability for someone to replace the screen and modify the module to take control of your phone – that's not a good thing at all.”