Microsoft Office 2016 Error "We're sorry something went wrong ... 0x8004FC12"
A solution search reveals lots of unhelpful websites with garbage answers. Here's the solution that worked for me. Enter the following in a Command prompt (DOS box) which has Administrator privleges. See Office 365 Activation Fix for more info. Can someone explain why these steps have become necessary?
net localgroup Administrators localservice /add
fsutil resource setautoreset true C:\
netsh int ip reset resetlog.txt (might be optional command)
Apparently this happens when the Microsoft Office Click-to-Run Service
become disabled. In my case I completely disabled it instead of setting it to manual start some time before the error occurred, and forgot that I did it. THIS page has some additional useful information and solutions for related errors.
Solution-1
Find the windows service application and run it. Then look for the Click-to-Run entry and make sure it is set to start. Then start it manually and try starting word (or excel etc) again.
Alternatively, if you're a command line junkie, you can accomplish the same through the Admin CMD window or Power Shell:
sc config clicktorunsvc start=auto
sc start clicktorunsvc
For other error and more details, see the link I provided.