Apple has released a software update for iPhone and iPad users who found that their devices stopped working after going to third-party technicians for repairs.

The problem, known as Error 53, bricks your phone if any non-Apple source tampers with the newest version of the Touch ID fingerprint sensor, installed on the iPhone 5s, 6 and 6s and some models of the iPad.

Apple has said it was designed as a security feature to prevent unauthorized access to the phone. But many users called the function a means to stifle independent repair shops that might charge less for repairs than those from an official Apple store.

Thousands affected

According to a report by the U.K.'s Guardian newspaper, Error 53 has affected thousands of people.

A Seattle law firm filed a class-action lawsuit against Apple over Error 53, calling the practice of rendering devices unusable if opened by a third party "abusive" to its customers.

"Despite knowing about the security features, Apple took no steps to warn consumers," the law suit says.

A post on Apple's blog details how to restore your phone if you've run into Error 53. It involves making sure you have the latest version of iTunes installed on your device and then a forced restart.

TechCrunch reports that restoring your phone this way will not re-enable Touch ID if it was disabled by the error. You'll still have to get that fixed by an official Apple technician.

"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," Apple said in a statement Thursday.