.. not sure... I had the same beta installed and for a long time I had no issue (though I tend to put the laptop into standby mode and only reboot it every few weeks, so not sure how long the problem had been there). My PC (used for gaming only), I do shut down and reboot, several times a day probably. That also was working fine until a week or so ago. Both the laptop and the PC started getting this problem, perhaps at the same time, whereas they'd both been fine running the MB software for several weeks previously. Very odd - it can't be coincidence: I do not regularly install Windows updates, as in my experience they create more problems than they solve - especially on the gaming PC.. I do of course have anti-spyware, anti-virus, firewalls etc. on both.
Logs attached from the laptop, which has the anti-ransomeware active and takes several minutes to close down. It boots just fine. (I suppose the MB service isn't shutting down properly). Hope the logs help.
Addition.txt
CheckResults.txt
FRST.txt