There's been a ton of online speculation — and condemnation — today. When contacted for comment, Apple provided the following explanation to iMore:

"We take customer security very seriously and Error 53 is the result of security checks designed to protect our customers," an Apple spokesperson told iMore. "iOS checks that the Touch ID sensor in your iPhone or iPad correctly matches your device's other components. If iOS finds a mismatch, the check fails and Touch ID, including for Apple Pay use, is disabled. This security measure is necessary to protect your device and prevent a fraudulent Touch ID sensor from being used. If a customer encounters Error 53, we encourage them to contact Apple Support."

Is this a new problem?

Some of this isn't new. Back when the iPhone 5s introduced Touch ID for the first time, former iMore editor Ally Kazmucha discovered there was hardware based security at the component level. That way, if someone took possession of your iPhone they couldn't bypass the encryption and get at your data. In other words, to protect us from both big and little brother.

What is new is the iOS 9 update causing "error 53" which, in defense of those who've received it, is completely opaque. As the old saying goes, security is at constant war with convenience, and it looks like some new check put in place as part of iOS 9 generates that error when it can't verify that hardware security is still intact.

Why is this only affecting third-party repairs?

It can actually affect any repair. If an error occurs following an Apple or Apple-certified repair, though, they can swap out the device for one that works, you can restore from backup, and everything is fine. With third-party repairs, not so much.

There are some complaints that about repairs not involving Touch ID that also cause the problem, though it's tough to rule out accidental damage. If true, though, it's possible Apple may need to fix the process so only the security system, and the security system alone, can trigger an error. And, of course, provide a more human-understandable error.

Why can't I override the security check? It's my phone!

Some have asked for an override that would let an owner opt-out of the security check. Unfortunately, once a "back door" exists, it exists for everyone. It's one of those things where security and usability clash, and why "fail safe" and "fail secure" are two very different things.

In other words, if you can override it, someone with bad intentions could override it as well.

Shouldn't Apple warn people about this?

In theory, absolutely. In practice, how and when Apple could provide such a warning is tougher to figure out. Putting in on-screen as part of the on-boarding process is unwieldy and doesn't scale. Putting it in fine print on the paper inside would likely be as good as no warning at all.

So what should I do?

If you live near an Apple Store or an Apple-certified store, go there. If you don't, and you can mail your device to Apple, consider that option. If you have the error 53 problem, contact Apple support.

If you've been affected by "error 53" let us know in the comments!