If you have tried multiple times without success follow the last three words in the message:

...contact customer care.

Use the Contact Us link at the bottom right corner of this page and then navigate to the appropriate customer care link.

I contacted Apple and was told that their engineers were working on a fix and that I should check the Apple support site to see when one was available.

Great service !!!

Apple halts iOS 9.3 updates for older iDevices due to growing Activation Server Lock issues.

Unfortunately, Apple didn't stop the update so now I'm stuck with a nonfunctional machine. Any fixes inthe making?

There are some official recommendations from Apple Support:

If you can‘t activate your iPhone, iPad, or iPod touch after installing iOS 9.3

Try alexey911's link.

Hopefully, this solution is still a valid one.

I was recommending this link until Apple issued the statement that it is halting/limiting downloads of iOS 9.3.

So, I am uncertain if this possible fix will still work or not, at this time.

Good Luck!

I assume you are being ironic when you say Great Service. We are locked out of our iPhone since 3-23-2016.We tried the recommended solution but the reset link is being sent to an old email (this took an hour to figure out). Waited in the phone que for 20 minutes. Apples said they would change my old reset email address to my apple id which is my gmail address, but that I have to wait 24 hours. Waited 24 hour but the reset email is still being sent to the old work email address. ( we disagree on what my seldom used password, school friend, old car, etc. questions). Got a Case ID yesterday but that link goes to "

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benfromfort wayne wrote:

 

Unfortunately, Apple didn't stop the update so now I'm stuck with a nonfunctional machine. Any fixes inthe making?

You didn't mention what iPad you have, but if it is an iPad 2, see below.

If you can’t activate your iPad 2 (GSM model) after you update to iOS 9.3 - Apple Support

I have spent several hours over the last couple of days talking to three Apple techs and wasted several hours trying different steps to activate my I-PAD. Two of them said it was caused by IOS 9.3. One did not. The final chat session tech said I have to wait for their Engineers to come up with a solution. Do not know when that will be. Really disappointed in Apple with this one. Any one had any success getting their I-PAD activated?