My messages app won't open, after I sent a large iMessage. I think it just has too much data on it. What can I do other then reset my iPhone?

Try force closing the Messages app: from the home screen, double-tap the home button, locate Messages in the list at the bottom, tap and hold it until it wiggles, tap ➖ to close it, tap the home button again. Then try Messages again.

I'm not sure if it will do any good or not, but you could try turn iMessage off in Settings>Messages, the after a minute or so, turn it back on. Otherwise, you may need to restore your phone.

Did the message send successfully?

The only other thing would be to restore the phone as new, without using your backup. Then test Messages again. If it works, you may need to restore the backup, save as much of your data as you can, then restore as new again and start over. Or, you could make an appointment with the Genius bar at a nearby Apple store and have them take a look at things (though I don't know what else they would so).

Have you tired restarting your iPhone?

Settings>general>reset> reset all settings, reconnect to wi-fi network by reentering password to network. If that does not work, backup and restore, set up as new. If it still doesn't work after setting up as new, it is a hardware issue, call Apple and/or carrier for replacement options.

I went and added my number as a contact in my phone, sent a text message and hit the home button before it sent so that I would receive the text in my notification bar. Once I clicked it, It opened that text. I then hit messages and it took me to my inbox and I just deleted the entire thread. Everything is back to normal without resetting or restoring my phone.

Hi everyone, I had this problem but none of the solutions above worked. What happened with me, and with others in other forums, is that a particular thread or message was causing the problem. I'd go to open the message and all I'd get was a white screen with the blue bar at the top. So, I went into contacts, pressed 'send message' to a contact whose message wasn't causing the problem, then I pressed back to messages. You then swipe to the left on the thread that's causing the problem, and delete it. Sadly this means you will lose all that person's messages, but you can try opening it from there and deleting it on the thread. Didn't work for me though. Hope that helps! 🙂 It was the only thing that worked for me after about three days of total frustration and resetting!

Log out off iMessages through the settings app. then go to the app, and it will let you log back in. After you log back in, it should work

This worked and didn't have to go the extreme of resetting ipad! thank you!!

Have same issue here. I've tried to send message from contacts, but getting the same white screen and application crashes. I've tried to remove app from memory, reboot my iPhone pressing home+power buttons, logout from Messages but nothing helped.

iPhone 5 iOS 7.1.1

Any suggestions?

Solved my problem.

Go to your contacts, go to message them it will take you to your imsg screen.

swipe to left [the big message that is causing problems] delete that conversation

and everything goes back to normal!