If you're having issues updating older iPhones and iPads to iOS 9.3, Apple is working on a fix.
Update: Apple has released a new version of iOS 9.3 (build 13E237) to address the activation issues. You can download and install it now.
Some people with older versions of iPad and iPhone, have experienced problems updating to iOS 9.3. The problems stem from the password authorization required to complete activation. In an effort to address it, Apple is pausing the update for those devices and working on a fix, which the company hopes to release soon. Apple provided iMore with the following statement:
Updating some iOS devices (iPhone 5s and earlier and iPad Air and earlier) to iOS 9.3 can require entering the Apple ID and password used to set up the device in order to complete the software update," an Apple spokesperson told iMore. "In some cases, if customers do not recall their password, their device will remain in an inactivated state until they can recover or reset their password. For these older devices, we have temporarily pulled back the update and will release an updated version of iOS 9.3 in the next few days that does not require this step."
If you've already gotten into a problem state, for example by accidentally entering an incorrect password or if you weren't able to enter a password, Apple has posted a support document with a potential work around.
The steps involve signing into iCloud, activating via iTunes, or temporarily removing Activation Lock via the web.
If you've been having problems, please let us know which, if any of these steps, worked for you!