Q: Messages and FaceTime not working from any device

Hi,

I'm trying to get my son's iPad 2 Mini working with Messages and FaceTime (he's under 13, so the account is managed by me).

When I try to log in with his icloud.com account both Messages and FaceTime give me a message saying (for example, for Messages):

"iMessage Activation. An error occurred during activation. Try again"

When I try to log into my own Messages account on the same iPad, it works fine.

When I try to log into his Messages or FaceTime on a MacBook Pro, I get the same activation error message - so the problem appears to be with his account, not the device.

However, he is able to log into iCloud, Calendar updates are working fine. App Store purchased are working... The only problems are Messages and FaceTime.

Any ideas on what might be causing this would be appreciated.

iPad Mini 2, iOS 9.2.1

MacBook Pro (late 2011 15" : OS 10.11.2)

Cheers

- geoff