This ^.
Have tried turning power off/on, taken out sim card, reset network settings and nothing seems to work. (there was a ios update, so I did that, but it did nothing to fix this issue).
On the odd occasion, after these attempts, the app opens to show the messages, but when i tap to open the app hangs and eventually crashes or i shut it down myself.
I have also gone into the settings and tried to look at the messages settings in there, The same things happens. Upon pressing messages the settings hang!
This doesn't seem to be happening with anything else. Also I checked to see if I could view the messages on my Apple Watch and there it is, messages app seems to be working fine. I don't receive a huge amount of messages, to be fair, so don't know if I am receiving messages correctly, but I may have this functionality at least.
Any answers?