What you mean with "upload"?
Load the firmware again?
Or "save to device" a new "joystick" profile in MMjoySetup?
If you create a profile, e.g. with 1 button, "save to device" , test. etc,
and then change for 10 buttons and nothing more and "save to device", the Windows will not detect, because the VID/PID has not changed, so you need clear the previous entry in windows Register.
Anyway in this case games recognize the change, the issue is only with the obsolete Windows Game Controllers.
Yes, so it worked the first time so i could test a button. Then i added more buttons and tried to save to device. I have even tried starting the boot loader etc. So the CMD screen opens, the process runs, but it does not reflect the changes