accessories can cause the OIS to malfunction. On August 21, 2015, Apple instituted a repair program for iPhone 6 Plus models released between September 2014 and January 2015, citing faulty rear cameras on affected models may produce blurry pictures. Some iPhone 6 and iPhone 6 Plus models have an issue in which the front-facing camera is somehow "shifted", or out of place. Apple stated they would replace most affected iPhone 6 models with this issue, free of charge. Despite numerous complaints regarding this issue, it does not seem to affect the camera itself. It is said the camera is not what has shifted, but a piece of protective foam around the camera module itself that has gone out of place. "Error 53" If the iPhone 6 home button is repaired or modified by a third party, the device will fail security checks related to Touch ID as the components have not been "re-validated" for security reasons—a process that can only be performed by an authorized Apple outlet. Failing these checks disables all features related to Touch ID. Such effects have sometimes happened as a result of damage as well. It was reported these same hardware integrity checks would trigger an unrecoverable loop into "Recovery Mode" if iOS is updated or restored, with attempts to restore the device via iTunes software resulting in an "error 53" message. Beyond the explanation this is related to hardware integrity errors regarding Touch ID components, Apple provided no official explanation of what specifically triggers error 53 or how it can be fixed without replacing the entire device. On February 18, 2016, Apple released an iOS 9.2.1 patch through iTunes which addresses this issue and admitted error 53 was actually related to a diagnostic check for inspecting the Touch ID hardware before an iPhone is shipped from its factories. Touchscreen failure ("touch disease") Touchscreen control components on iPhone 6 logic boards have insufficient support, including a lack of underfill—which strengthens and stabilizes integrated circuits, and a lack of rigid metal shielding on the logic board unlike previous iPhone models; the touchscreen controller is instead shielded by a flexible "sticker". Normal use of the device can cause the logic board to flex internally, which strains the touchscreen IC connectors and leads to a degradation or outright loss of touchscreen functionality. A symptom that has been associated with this type of failure is a flickering grey bar near