Users in the Apple Support Communities have been complaining about issues since the iOS 7.0 update, including problems with the iMessage applications. Some users have found that their messages are not being sent or received. The issue doesn't seem to be with Apple's servers as these messages are sent as text messages when the user cannot be reached.The number of posts related to the problem have increased since the September 18th launch of iOS 7 and has even continued after the iOS 7.0.2 update.
The following solution was posted on the Apple Support Communities forum for users to try out: First, disable iMessage in Settings > Messages. Next, reset networking settings in Settings > General >Reset. Finally, re-enable iMessage in Settings > Messages. The downside with this method is that your iPhone will forget previously entered Wi-Fi passwords.
Some users have also found that turning off their iOS device for a few minutes and then turning it back on would also fix the issue.
Apple's iOS 7 has faced its share of issues since its launch. Apple almost immediately released the iOS 7.0.1 update to fix an issue with the Apple iPhone 5s fingerprint sensor. Then iOS 7.0.2 was released to repair a bug which allowed users to make phone calls on a device which was protected by the lockscreen. It also fixed a bug which allows unauthorised users to disarm a locked iPhone and enter the owner's camera roll. Pictures could then be edited, deleted or shared with social networks.
We hope Apple will have a quick response to the latest iOS 7 issues and help maintain a positive outlook on their latest platform for their users.
source - MacRumors | AppleInsider