I have just had a bit of a scare. All is OK now but wondering if I did something wrong. I have only been running my Windows 10 Bootcamp via Parallels 12 in Sierra 10.12.2 for a week, and for the first time I ran Windows Update from Parallels. There were a lot of updates including an OS build update. All took quite a while but seemed fine at the end. Then I tried to boot directly into Bootcamp, and got the dreaded "No Bootable device message". Tried twice. I rebooted to Parallels and reinstalled Parallels Tools because I couldn't think of anything else to do. Then rebooted to Bootcamp but by holding the alt key while restarting, and selecting Windows from there, instead of using the usual Start up disk System Pref pane. Bootcamp booted OK (phew!) Then I tried to reboot to Mac using the Bootcamp Control panel, but it kept rebooting to Windows. So I shut down and reset the NVRAM by booting holding alt+opt+P+R Machine restarted in Mac. Now Bootcamp works properly and will restart to Mac from the Control Panel. Question: Is it a mistake to do a major update of Bootcamp from Parallels? I think I will avoid doing this in future unless I learn something new from this thread.