Several people on the TechNet forums (and other interwebz sites) have encountered error 0x8004FC12 with Office 2013, 2016 and even Windows. It seems most of these cases have gone unresolved or only gotten fixed by refreshing or reinstalling Windows. I recently found myself in the same boat. When I would try to activate Office 2016, I received the error:
“We’re sorry, something went wrong and we can’t do this for you right now. Please try again later. (0x8004FC12)”
The application event log had:
“Acquisition of End User License failed. hr=0x8004C12”.