Sim Not Valid after iOS 9.3 update

Activate the phone using a German card, insert your Bulgarian card and continue using your phone.

yes, that is what I did.

But, after re-inserting the Bulgarian sim card, on the screen appear "Activation Required", after swiping - the same problem.

Interesting that, after inserting the German sim card again - the phone asks me again for activation. After already activated once with the same German sim card.

I can't figure it out what is happening.

I have had the same problem today. Swiss operator. Apple told me to get a new sim card in order to help them troubleshoot (now they are offline). The new sim did not change anything. I did receive a call from another phone, with the old sim, which I was able to answer - surprising... still, I cannot get past the SIM Not Valid screen

This is a very stupid problem!!!

I activated my iPhone with a German prepaid sim card. And with that card the phone is working normally.

But, once when I insert the Bulgarian card - Apple logo, then "Activate Request", and the same problem with the SIM NOT VALID appears.

I haven't contacted Apple directly yet, but if they write you something, I'll be glad if you share.

Posting the same question twice is not going to change the answer.

Still searching for the "answer"!

Try a sim from a third (different wireless) provider. If you do not have

access to another sim, borrow one from a friend/relative/co-worker for

the few minutes it will take to see what happens when using their sim.

If that sim works, the iPhone is unlocked and either the Bulgarian sim is

defective or the Bulgarian wireless provider is not supported - in which

case you have to deal with the Bulgarian wireless provider to resolve the matter

and it may turn out that you will not be able to get the iPhone to work with that

Bulgarian provider.

If that third sim gives the same error message, the iPhone is locked. Only

the cellular carrier to which an iPhone is locked can unlock it. Not all do, some

require you to be a current customer in good standing, some charge a fee.

Thank you for the kind support, but, please, read what I've already done in my previous posts.

My iPhone is NEVERLOCKED.

I activated it with a German sim card, but it doesn't work with my Bulgarian sim card, which I use with this iPhone since I bought it (Dec. 2012).

There is definitely something wrong with the iOS update, not with my iPhone.

I'm still waiting for Apple Support to respond.

Apple is not here - you will not get a response from Apple in this forum.

This is a forum for users to help other users with technical questions.

What is the name of the Bulgarian wireless provider whose sim you are trying to use?

Is it a supported wireless provider?

Your iPhone works with the German sim, so the iPhone is not faulty.

What does it say when you look at Settings>General>About>Carrier?

You may have to scroll to see the entry for Carrier.

In what country from what retailer was the iPhone originally purchased?