Using the latest Cubase 8.5 and Groove Agent 4.2
Start with a new project and adding Groove Agent as a VST Instrument.
Clicking on Drum Map, “Create Drum Map From Instrument” is grayed out.
How do I enable this feature? I am trying to follow a tutorial and am stuck at this step.
did you load some kit in Groove Agent ?
Yes, drum kit and patterns loaded.
Interesting note here, I had loaded Acoustic Agent Vintage Kit. Again, trying to follow a tutorial here.
Deleted instrument, Reloaded Groove Agent, (clean project with only GA instrument track).
This time I loaded up Acoustic Agent Rock Kit.
Now “Create Drum Map From Instrument” is active.
Thanks Lee!
I was having the same problem but I followed your procedure and now it works! 
Create drum map function is only possible with VST3 instruments, maybe a vst2 version was loaded?
No BFD3 is not VST3 and create drummap is avaible in cubase !
Hi,
Just re-qouting things.
Create instrument maps is a VST3 function, however it could be built-in into vst2 instruments it seems.
Steinberg Developers must give better user feedback. Importing Drum Maps from Virtual Instruments