New Upgrade of my Phantom 4 always failing I need some help please !

What have you done so far ?

When I upgraded the aircraft to the latest firmware I did the following:-

Make sure the latest App' is loaded on your display device (V2.8.0)

I then downloaded and installed DJI Assistant (from the download page this includes additional USB driver, which is part of package) onto my desktop computer (Windows PC).
Plug aircraft into computer using USB lead and power up aircraft.
Run DJI Assistant, it should display an icon for the P4 as a device. Click on this and after a minute or two (I assume computer is connected to internet) it will display Current and previous version of aircraft software. Sellect latest build and click 'upgrade'.
If all going well then the LED beside the USB port on the aircraft will start flashing green/red, when update completed (20-30 minutes or so ) then this LED should be steady green. At this point the aircraft can be disconnected from computer and rebooted (switch off then on again).
Then with the display device connected to the RC (display device needs to be connected to internet as well, wifi) and the aircraft powered up, run the DJI GO App'. After a short while it should indicate that the RC needs updating (I'm assuming here that it does need update), select update and the RC should update via the display device wifi. When completed I would power all down. Then power up aircraft, and after a few seconds the RC, then display device. Run the DJI GO App' and you're almost ready to fly.

Hello Pierre, did you upgrade your drone via DJI GO app or DJI assistant 2 ? If it keeps failed, you can upload the log and post the public link here. Here is a video of how to find the upgrade log:

I was finally able to upgrade my Phantom4 with my MacBook Pro & DJI Assistant 2.