I had the issue uploading the Firmware with the Leonardo I got last weekend too, Windows 10 would not load the Drivers from the latest Firmware Package (2016-11-01)(driver enforcement?) so I used the drivers in the Arduino IDE 1.613 zip package to get it recognized. However the Reset button just would not "reset" the Leonardo to bootloader mode , it would disappear and almost instantly reappear on the same Com Port. Reading about the GND and RESET Pin on the Pro-Micro and touching it twice quickly gave me the idea to quickly push the Leonardo Reset button quickly twice and it worked and it gives me 5-8 secs to hit the Firmware download button now. ( A new Tip for the Wiki maybe?)
MMjoy2 seems to have loaded the Firmware now but the L-LED is now constantly lit on the Leonardo ...is that correct? maybe just me doing something wrong ? as I have only assigned a single button (correctly?) so far so it would be seen correctly in MMjoy2/Windows but the Windows Game Controller Window is calling it the MMJ-Reset and if I try to open the advanced options it throws an Error stating Your Game Controller is not Connected correctly.
I currently have nothing attached to the Leonardo , which may explain the error? I am just starting this endeavor as I have a gameport FLCS16+TQS and CH Pedals that I have had for many years (nearly unused) with the Stickworks Digital Chips installed , though I still have a number of the Old Chips as well as some new TM Pots and Hat Buttons I got before TM stopped selling them.
Micro Electronics and Arduino are new to me ,soldering/metering etc is not, so there will be a few questions I am sure but I am hoping someone knows of a good Writeup/Tutorial on converting the FLCS16+TQS specifically that would be a massive help....
So far I am about 65 pages into the thread so still plenty of reading to do , thanks guys.
KB
PS not as new around here as my post count would indicated when did EF2000 come out , just had to get a new account to post..
Edit ... also curious if anyone has tried the MuxShield II and if it would work with the Leonardo , it seems to give 48 pins vs the Leonardo's 20...
and it gives me 5-8 secs to hit the Firmware download button now. 
