Uploading problem "Invalid DFU suffix signature"

Official Hardware Portenta Family Portenta H7
2

This "Invalid DFU suffix signature" is always there (also on my system).
You can ignore it.
As long as you see "Download done" - it should be fine.

I see this all the time when flashing the board:

download	[=========================] 100%       263412 bytes
**Download done.**
**Warning: Invalid DFU suffix signature**
File downloaded successfully
	The upload process has finished.
A valid DFU suffix will be required in a future dfu-util release
Transitioning to dfuMANIFEST state

Some hints, I have realized when using the UART flashloader:

  1. press the reset button twice (or several times) until you see a green fading flashing LED
  2. close any UART terminal still connected with your board (flashloader will fail)
  3. when you have also AC6 STM System Workbench open (I use MSMicro but use it as reference for older projects to merge code) - it conflicts!
  4. Select the right COM port in MSMicro (ArduinoIDE)
  5. ATTENTION: changing to a different board, but same type - will change the COM port used for it
  6. after my project was flashed and running 1st time properly - I got a different COM port for it (change in IDE) - check which COM port is used via Device Manager,
    check if your COM port has changed for this board
  7. Check really carefully if you see a "Download 100%" or "Download done" message:
    The larger my project gets - the more often I see a stall on download (it has not completed)!

You can also try to flash *.BIN file with CLI:

dfu-util -a 0 -d 2341:035b --dfuse-address=0x08040000:leave -D H7_SPIder.bin

Also seen, in office (trying to use board for industrial, company purposes): the UART based flashloader does NOT work at all: I guess: it pops up in Windows system as an USB device. And this is prohibited. So, I have no chance to use and flash this board in office (with strong IT policies where USB devices are disabled).

Portenta H7 is very sensitive. And it can be bricked easily (I have one already gone). Any "mistake" in your FW can make it inoperative (to access again, to use UART flashloader again). The SW/IDE for Portenta H7 is not really intended for professional and commercial use. Sorry (Dear Arduino team).