Have you tried to upgrade it through DJI GO 4?
If it fails to update after trying several times, then please click on "Upload error log", we'll analyze the log for you.
May I know what have you done to troubleshoot this issue? Could you please also click on 'Update error log', then provide me with your DJI Account email?
There seems to be another problem; DJI Assistent 2 does not show the Phantom4 icon, so I can not connect anymore to my W10 laptop nor my iMac.
Why is it gone? Doesn't DJI support firmware or software anymore?