My iPhone 4S Messages App Won't Work?

My friend had sent me an iMessage that restarted my phone for a bit. I was able to open the app a minute after, but then it crashed and it won't open again! I tried doing a hard reset, turning the phone off and on again, and it still won't open. If anyone could help out, it'd be really appreciated!

Go into your photos and send your friend that sent it a photo of whatever. You should be able to open it after that.

Make sure on message setting it says send as sms or mms. Check receipts contact info or you could restart your device. These are the only methods I know of. Probably more out there.