I have a problem with iMessages.
For 3 years everything was working ok, and yesterday my iMessages stop working.
In settings menu under iMessages I activate iMessages and there is messages waiting for activation, but I waited for few hours and nothing happened. I restored iPhone, log out and log in form iCloud and apple id, but nothing happened. Normal sms and calls are ok
I experienced the same problem and the timing was not related to an update. I am on iOS 7.0.4 and my iMessage and FaceTime stopped working midday for no apparent reason and would not re-activate. I tried several suggestions noted on the message boards and had no success with hard reset or network resets. I really wanted to avoid a full restore.
When all was said and done, I noticed my iCloud storage was almost full. I only had 70mb available. Immediately after deleting some things out of my icloud storage, I was able to successfully connect my phone to iMessage and FaceTime.