All Sms of one contact lost!?

Hello everyone!

I have a problem with my beloved Meizu m8..
Today i was just about to send a sms to my friend when my Meizu just crashed. The things on the screen were in a different position and so i decided to just wait for a few minutes to see if it's getting normal again.
Unfortunately the screen was just frozen and didnt react. So i pushed the home button to return to the home screen and went back to the inbox to check whether my sms was being delivered. And then i found out that all my sms with my friend weren't there anymore and the "Back, Reply, Edit" buttons are missed aswell! The only button i still can see is "display more", but of course it doesnt work aswell..
I restarted my phone twice but nothing changed! And appearently i cant receive sms of this friend!

Do you know what could help? Cause i'm lost
Thanks guys!!