Why does my iPhone 4S demand a valid sim card to function after update to IOS 9.3?!?!?!?

Because it's a phone. A SIM is required to activate it. It's been like that since the original iPhone came out in 2007.

Sorry but that is not true. I have updated my iPhone several times without a valid sim card inserted.

It is not Apple choice if I should want to use my iPhone as an iPod. So NO! they can not demand that I insert a valid sim card!

They can and they did. Sorry.

You can rant all you like. It won't alter reality at all. The SIM doesn't have to be tied to an active line of service, but it does have to be present. This is not new.

But that is exactly what it does demand. An active(!) sim card! It is now asking for my PUK code for the old sim card, that has been inserted the whole time (a PUK code I do not have anymore).

Arrogant Programming Produces Large Emotions (APPLE)

(HOW TO FIX) Invalid SIM after updating to iOS 9.3

Hi

You can just get another simcard or ask the network provider of the simcard you have for the P U K code.

Cheers

Brian

Sorry about my previous reply with link. I didn't see where it asked for a PUK. Just thought it said Invalid SIM. Yeah, if it's asking for a PUK and it's the SIM your carrier has on file for you in their system, we can give it out to you with no problem.

I have found a solution to my problem, as I found an old, and also no longer valid, sim card I have bought while traveling in the US a few years back. As this Telekom sim card is without pin code(?) it apparently solved the issue. Hurray for Telekom, not throwing old sims away and traveling abroad.

Still not pleased with the policy of Apple, and I feel for the people, who has found themselves to be the proud owner of a "brick".

Thank you all for your time and assistance.

It's a phone for crying out loud. Of course it requires a SIM.