If you haven't yet installed the iOS 9.3 update on your iPad 2, you might want to hold off as some users are claiming that the update is causing them to have difficulties reactivating the device.
Threads on Apple's support forum detail the issue. Basically, after installing iOS 9.3 the iPad 2 fails to activate, leaving users in limbo and unable to use the tablet.
The following error message is displayed:
"Cannot activate because the activation server is temporarily not available."
Some claim that the issue is simply Apple's activation servers being unable to cope with the workload on launch day, but others claim to have been waiting for their iPads to reactivate for over 24 hours.
A couple of possible fixes have been put forward. These are:
ZDNet has been unable to reproduce the issue on similar hardware.
I'm also seeing sporadic reports from some users claiming that apps are missing following the update. However, it seems that in most cases a reboot brings them back (press and hold both the sleep/wake button and the Home button until the device reboots and shows the Apple logo).
I've also seen reports from some users who believe that there's been a problem with their iOS 9.3 update because the Night Shift feature was unavailable. Note that this feature is only available on devices that feature a 64-bit processor (the iPhone 5S and up, the iPad Air and up, and the iPad mini 2 and up).