Worked for me too! I had also reset network settings, then realised I had disabled set time automatically and location settings - reset and all fine now, thanks!
None of the solutions seemed to have worked for me. iOS 6.1.6 iPod touch 4th gen
I spoke to a senior advisor this afternoon and I was told it's a known issue and they are currently working on it. He told me it could take up to a couple of weeks to resolve. We will all have to sit tight and wait I'm afraid
in Settings/iCloud click on your name and if it asks for your password enter it. Then go back to iMessage or FaceTime and try to login.
Retrieving data ...