QGC firmware upgrade cancelled

Hello I have tried to load the firmware to the board following the user guide documentation. I have issues in the first step, connecting the device (Mateksys H743 wing), since I do not know why the upgrade process is cancelled. The board is only powered by USB and it is connected directly to a USB port. I would appreciate any help since this is the first time I use QGC.
Thanks in advance, regards.

Happens sometimes. Try a different USB cable and port and make sure you have nothing else plugged into the FC.