Apple has released a new version of iOS 9.2.1 and apologised to customers after owners who had third party repairs on some iPhones were locked out by an "Error 53" message.
An iOS update led to some iPhone 6 and 6 Plus owners that had undergone third party repairs to receive a message that would then lock them out of the phone.
The new update provides a resolution for the affected phones through iTunes Store.
The phones affected had been serviced by third party repairs around the home button, and Apple said the issue arose around the security of the Touch ID.
"Some customers' devices are showing 'Connect to iTunes' after attempting an iOS update or a restore from iTunes on a Mac or PC," a statement to TechCrunch from Apple said.
"This reports as an Error 53 in iTunes and appears when a device fails a security test. This test was designed to check whether Touch ID works properly before the device leaves the factory.
"Apple released a software update that allows customers who have encountered this error message to successfully restore their device using iTunes on a Mac or PC.
"We apologize for any inconvenience, this was designed to be a factory test and was not intended to affect customers. Customers who paid for an out-of-warranty replacement of their device based on this issue should contact AppleCare about a reimbursement."