iMessage immediately closing when I try to click on messages to go in and send text

I have an iPhone 6, haven't updated IOS in a while and have had no issues whatsoever until yesterday when I went to sen a text. I can click on the message screen and scroll down through it, but when I hit on a group/individual message to send a message or look at past messages it immediatley backs out to home screen. I've tried the hard reset, turning iMessage on then off, and resetting to network settings. Any other thoughts on how to fix it? Thanks