In reply to Stu Tyrrell:
The screens for apple phones consist of several parts that are bonded together - outer glass, digitiser, LCD screen and finally the backlight. Quality varies and higher priced reputable repairers will be using the exact same spec as apple (probably made in the same factory as the apple screens) There are cheap screens out there that are junky, probably factory seconds. It took me a while to nail down a good supplier of quality parts.
This latest 'problem' exists not because of the screen being replaced but because of the biometric home button has been replaced during the screen replacement repair.
On the iphone 5S, 6, 6S and higher end ipads the home button serves as the finger print reader. The finger print data is stored on an IC on the button ribbon cable and not on the logic board. When the screen is removed it is very easy for the ham fisted or inexperienced to lift the screen too high off the frame and tear the ribbon cable. This is a disaster as the fingerprint data can never be read by the phone however the button, ribbon cable and IC can be replaced along with the screen and everything is good, or was until this latest update. The update process will check the home button security id against the database from when it was manufactured and if they don't match its 53 error code.
Reputable repairers know all about this and forearmed is forewarned. They'll use tools such as a padjack or an ishclack which lift the screens but limits the amount they lift them not to damage the ribbon cable so it can safely be disconnected then before the entire screen is lifted.
I suspect full details of the IOS security features are contained in the small print and users agree to them by downloading and installing the update.