I had to downgrade my DJI Phantom 4 Pro Aircraft firmware to have image transmission again.  I like to keep my drone, controllers, and tablets updated, but this has not worked for me with the latest firmware upgrade.  (Both controllers and tablets have current upgrade).  GL300E, and GL300F controllers.  GL300E controller with screen with DJI Android... / GL300F controller with IPad Mini 4 (WiFi only) IOS tablet, and with NVIDIA K1 Shield Android tablet.  I have upgraded and downgraded all with factory resets several times.  Each time I go ahead and upgrade to current aircraft firmware again, I have no image transmission.  It all started with the Aircraft Error (0x20) and the Fly Safe upgrades.

Hi I’ve got exactly the same issue with m’y P4P. Sole Times the image transmission comes back after a round 2 minutes, but sometimes never. Did you find out on your side ?

I have downgraded all firmware on the controllers, tablets, and aircraft, 2 steps.  I have also deleted, then reinstalled the DJI Go 4 App.  I have then started with factory resets, and upgraded all firmware to the latest firmware, 1 step-up at a time, except for the latest "fly safe" upgrade.  I have the latest "fly safe" on my aircraft, but not on my tablets.  All seems to work well now, but because of the weather, I am not flying much, and I am only flying with the Litchi App; and mainly Waypoint flying only.  I am also using the Litchi App for limited regular flights.  No problems.  I use the DJI Go4 App for settings but fly in Litchi.  When changing controllers I just re-pair my controller with the aircraft.  I will know more when the weather gets better and I am flying in the DJI Go 4 App.  NOTE:  I do not have the DJI Go4 App and the Litchi App downloaded together in any tablet.  I use a specified tablet for the Litchi App, and specified tablets for DJI Go4 App.  Hope this is helpful.  (A lot of working with the drone and controllers and tablets, but I can fly now, problem free!

Thanks a lot. I’ll try to do the same as you did. Wish you good flights when weather us ok.