windows update failure 3 lumia 950

[Windows Central Question]

I have a Lumia 950. Recently it started randomly rebooting whilst I'm the middle of texting, or when I get an incoming call or actually when ever it feels like, it doesn't seem connected to any one app. I have factory reset the phone 3 times and it appears to have had no positive effect. I download 'field medic' and started logging and the only thing I can see in the reports is 'windows update failure 3' Help!