Quick tip guys - especially if you have not watched Brian's videos.
Order of operations for some of these technologies is VERY explicit. Have just been playing with fabricpath, and could not work out why my port-channel members would not come up - the config looked absolutely fine!
Stripped it back a couple of times, and on the third attempt (using a different order of operations) the port-channel kicked into life.
The config was EXACTLY the same, it's just the system needs to have things done in a certain way, otherwise 'computer says no'.