I'm not a expert by any means and am stuck with upgrading my MacBook Pro to Sierra. I checked all the sys reqs before I went ahead and made a full back up - all looked good to go.
I downloaded Sierra from the App Store and followed the on-screen steps to set the upgrade in motion. Never had an issue updating OS so I went and made dinner and came back a bit later to find what appears to be the start up screen with the macOS Utilities window open asking me if I want to restore a Time Machine back up, reinstall macOS, get help online, or use the disk utility. So I'm not sure if there were any error messages during the process.
I can't find any reference to this happening online - perhaps because it's super basic and everyone else knows what to do!
I don't want to make it a bigger mess or do anything unnecessary like restore from back up if this is just a failed upgrade that if I restart all will be as if I hadn't tried to upgrade. I now have a sneaking suspicion that my existing operating sys might not have been the one able to go straight to Sierra. Would that have triggered an specific error message? Otherwise I have seen some reference to permissions being the issue - could that be the case? Can I fix this myself? Or should just take it into an Apple store and pay for support?