video freezes when recording

video freezes and stops recording causing me to miss many important moments. I have to close the app and reopen before starting up recording again. Has anyone else had this issue and is there a fix? It started a few weeks ago when every time I hit the red record button, the app would close. i ended up recording that day in slow mo because I couldn't get the regular video to work at all. Now it has happened 4 different times that I'll be recording and the screen either goes gray or just freezes and I have to close out the app and go back in to start recording again. Help!