Coherence mode greyed out on Parallels 12

Yes, I have, each time. And it happens only on the 13", not my other machines. Is there a better way to get service support in having someone 'look at my screen' as it's happening (similar to how Apple Joint Venture does it)?

 

I also had a similar problem (during late Sept 17) after installing latest Windows 10 security update, once Parallels 12 had loaded and when 'right clicking' the 'View' tab, I could not 'Enter Coherence' (it was greyed out), but was able to Enter and Exit Full Screen. After several attempts by repeatedly Entering and Exiting Full Screen, I discovered that 'in desperation' by (unchecking) 'Use All Display Adapters in Full Screen', this enabled me to 'Enter Coherence'. So I decided that after the Update, Windows must have tried to use all Windows generic WDDM drivers, hence had caused the problem. I have updated many times previously and never encountered this issue, so now think it must have been a conflict with too many Display Adapters being present in this case.