Error 53 happens when you have a problem with the Touch ID. If oyu spill liquid in to the recess of the switch or it develops a fault, error 53 is caused by a faulty home button or Touch Id sensor. I know because I’ve had this problem myself leaving me with a £250 bill to repair the phone. Only it’s not a repair I got a new phone.
Thats not stopped the Guardian taking up arms against Apple however.