Can't open messenger app

[plawansai]

How should I do?

Thank you very much.

 

[scifan57]

Do you mean the built in message app?

 

[plawansai]

No, it is a Facebook messenger app.

 

[J. A.]

Force close the app:
Double tap the Home button to show the App Switcher, then slide the thumbnail below the app icon towards the top of the screen.