I’ve tried your solution, but it isn’t working for me. I think it’s a connection issue. Not sure what though.
1- I’ve connected my other Mega 2560 and it updated without any glitch. There was nothing connected to it except the USB & the Network cable.
2- I then went back to my board, and tried a few thing. I was finally able to update it when I removed my Internet module from the Mega Board. I left all the other wires connected. The update took only few seconds. I then plugged the Internet module back to the Mega board and connected everything. My board was updated and everything works fine.
The only thing connected to the Internet module are CD74HC4067 modules that I use for input switches. I’m not using any power from the board, all of my power devices are fed by external 5 volt sources.
Thanks agin for you help.