my iphone 5 messages keeps shutting down

Hello tommyyyy666777,

Welcome to the Apple Support Communities!

I understand that the Messages application on your iPhone is shutting down unexpectedly. To troubleshoot this situation, I would suggest restarting Messages, restarting your iPhone, and checking for updates.

The attached article is written for applications downloaded from the App Store, but the first three steps are valid for your situation.

If an app you installed unexpectedly quits, stops responding, or won’t open - Apple Support

Restart the app

Close the app and open it again.

Restart your device

Turn your device off and back on.

Check for iOS and app updates

1. Make sure that you're using latest version of iOS.
2. Open the App Store and tap Updates.
3. If updates are available, tap Update All.
4. If asked, enter your Apple ID password.

You might need a Wi-Fi connection to update some apps.

Have a great day,

Joe