birdmanmike

There are. 
 
Look in the FTN folder at the revision notes and the bit about setting [legacy]  enabled=1.  That worked for me, same problem.  The gtn_config.ini for the enable=1 is in the Flight1 Aviation Technologies\GTNGauge or GTN folder in appdata\roaming. Also copy the .ini into the Flight1 Aviation technologies\GTN folder if not there (where it should be anyway) as otherwise seems to repeat problem sometimes.
 
As per the revision notes, it doesn't give this problem for everybody.  you must have the right version installed it seems because otherwise you wouldn't even be able to config the 750 in the Duke :smile:

Extensive searching found the solution if anybody else gets it.  Found where people with Assassins Creed get the nvapi.dll_unloaded  error in Event Viewer causing a fatal.  Whatever, go to SysWOW64 in Windows folder and search nvapi.dll.  Delete it  or back it up somewhere. Error goes away. Why?  GOK

No more flagging from SE with latest version so, thanks, for me solved.
 
Mike

Yes, I'd built a new machine.  Have been in contact with Ben from MCE following above from MCE and it's now all sorted, very quickly.  He/they have been extremely helpful - another example of the great support from the MCE team.  Thanks to all of them.
 
Cheers, Mike