I am, right now, trying to reboot an iPad 2 after updating it to 9.3.1.
And I'm getting the activation error.
This, after updating to 9.3 and then having to downgrade to the last iteration of 9.2.
So... I don't think it's quite as safe as this reports.
I've tried removing an old SIM card and rebooting, in hopes that would work. It didn't.
Now I'm trying this... (from here: If you can't activate your iPhone, iPad, or iPod touch after installing iOS 9.3 - Apple Support)
Try to sign in to iCloud.com, so you can remove Activation Lock:
- Turn off your device or take it offline.
- Sign in to iCloud.com with your Apple ID and password.
- Open Find My iPhone.
- Select All Devices, then select your device.
- Click Remove from Account. If you still see a map in the device detail view, select All Devices again, click
next to your device, then click Remove. - After you set up your device successfully, make sure that you sign in to iCloud and turn on Find my iPhone again.
It's still rebooting after removing it from iCloud, so we'll see if that works...
And... nope. That didn't work either.
So now I'm going to try this...
If you can’t activate your iPad 2 (GSM model) after you update to iOS 9.3 - Apple Support
(Link has the same name as above, but it's different info... on how to restore the iPad)
Really bummed that this happened, because this time I don't have a recent backup... so if I have to do a full restore, it means tossing two weeks worth of Minecraft projects for my daughter... plus losing progress in four downloaded spelling apps. Grr.