I have not flown my P4 for awhile so I checked the firmware and it need upgrading.
I downloaded the latest Assistant 1.2.4, and statred the process.
The download reaches 100% then fails.
Have rebooted the computer, drone and software a number of times only to get the same result. I have tried different cables also.


The P4 is in perfect condition, I had a P1 for a few years before I bought the P4 so I could fly alright.
I can fly without the upgrade but I think I would prefer to get this sorted.

When it reaches 100% then wait for a minute or two, there may just be a delay in Assistant confirming completion.

With all connected and powered up you can also check 'About' in the 'General Settings' menu in DJI Go 4, that should list all builds. And update for aircraft could be initiated there if required provided the display device has a good wifi internet connection for downloading files.

With latest update you also need to make sure RC is at V1.9.3 as well, otherwise there will be poor communication between RC and aircraft.

Hey there, what's the current aircraft and controller firmware version? Please launch DJI GO 4, enter General Settings, click About to read the version number.

DJI Susan Posted at 2018-5-19 02:57
Hey there, what's the current aircraft and controller firmware version? Please launch DJI GO 4, enter General Settings, click About to read the version number.

HI Susan,
App 4.2.14
Remote controller 1.6.0
PFSD App  01.00.1.09
BFSD         01.00.01.07
Aircraft V01.02.0602
Thanks Richard

Aardvark Posted at 2018-5-19 01:51
When it reaches 100% then wait for a minute or two, there may just be a delay in Assistant confirming completion.

With all connected and powered up you can also check 'About' in the 'General Settings' menu in DJI Go 4, that should list all builds. And update for aircraft could be initiated there if required provided the display device has a good wifi internet connection for downloading files.

Thanks for your input Captain, within a few seconds of the firmware update reaching 100% a message appears showing the process has failed and asks if I want to down load a log file.

Is your remote powered off? - from your initial post at #1 it sound like it fails in the end of the download and newer start the upgrade part?
Try after power off the controller, removed SD in aircraft and after a reset to factory settings in Assistant2.

If still failing, download the log and post it to Susan or other Admin.

KedDK Posted at 2018-5-20 02:52
Is your remote powered off? - from your initial post at #1 it sound like it fails in the end of the download and newer start the upgrade part?
Try after power off the controller, removed SD in aircraft and after a reset to factory settings in Assistant2.

The controller was not powered on whilst using assistant other than when I tried to check through Go4, trying through Go4 caused go 4 to hang whilst checking aircraft for firmware update.
I am using windows ten, but I assume so are many others.
I tried removing sd card but unsuccessful.
Will try restoring factory settings but I have been reluctant as I can still use the drone, so I am concerned factory settings may upset upgraded controller interaction.

QuestB2 Posted at 2018-5-20 03:47
The controller was not powered on whilst using assistant other than when I tried to check through Go4, trying through Go4 caused go 4 to hang whilst checking aircraft for firmware update.
I am using windows ten, but I assume so are many others.
I tried removing sd card but unsuccessful.

Yes the reset to factory will reset all custom settings on the aircraft including the camera settings but even if it still fails to upgrade i believe you would still be able to correct your settings again if you have that possibility now.
Can you confirm that the download complete and that it is during the transfer or upgrade it fails?

KedDK Posted at 2018-5-20 03:53
Yes the reset to factory will reset all custom settings on the aircraft including the camera settings but even if it still fails to upgrade i believe you would still be able to correct your settings again if you have that possibility now.
Can you confirm that the download complete and that it is during the transfer or upgrade it fails?

It is during the upgrade it fails after the download.

QuestB2 Posted at 2018-5-20 04:20
It is during the upgrade it fails after the download.

Strange but i am not surprised at all.
another thing to try could be a previous version of Assistant2 like ex v.1.2.3, the older versions might be found at phantomhelp.com if you don't have them already.

Best luck.

KedDK Posted at 2018-5-20 04:32
Strange but i am not surprised at all.
another thing to try could be a previous version of Assistant2 like ex v.1.2.3, the older versions might be found at phantomhelp.com if you don't have them already.

I started with a previous version and did not get the option to upgrade. Once assistant was upgraded it all looked good until the firmware up grade fail.
I just tried to send the log file to DJI via assistant but the software will not accept my mobile number so I can not send that either. Ah the joys of modern technology.

The same thing happens to me, I've tried different devices and nothing does not update me

KedDK Posted at 2018-5-20 04:32
Strange but i am not surprised at all.
another thing to try could be a previous version of Assistant2 like ex v.1.2.3, the older versions might be found at phantomhelp.com if you don't have them already.

I already got it, I installed an update of assitent previous 1.2.3 and I have updated it. THANK YOU VERY MUCH FOR YOUR HEL

QuestB2 Posted at 2018-5-20 04:47
I started with a previous version and did not get the option to upgrade. Once assistant was upgraded it all looked good until the firmware up grade fail.
I just tried to send the log file to DJI via assistant but the software will not accept my mobile number so I can not send that either. Ah the joys of modern technology.

"but the software will not accept my mobile number so I can not send that either"
Been there tried that too ... in an attempt to upload some flight logs +45, 0045 with and without spaces nothing was working i even tried several of DJI's own numbers listed on the support pages and it just keep complaining that there was an error in the phone number.
Never figured that out and ended exporting to local drive hoping they can retrieve it if needed at a later point, just love their engineering skills ...

phantomtambo Posted at 2018-5-20 10:46
I already got it, I installed an update of assitent previous 1.2.3 and I have updated it. THANK YOU VERY MUCH FOR YOUR HEL

Glad to hear that it worked for you, hopefully also QuestB2 find a way trough at last.
What version worked for you? it might could be the light for OP too.

QuestB2 Posted at 2018-5-19 17:56
HI Susan,
App 4.2.14
Remote controller 1.6.0

Richard, sorry for the late response. Please kindly export the upgrade log for analysis, we'd like to look into the exact status, thanks so much!

Assistant 2(Windows) C: /Users/XXXXXX/AppData/Roaming/DJI Assistant 2/upgrade_log

phantomtambo Posted at 2018-5-20 10:46
I already got it, I installed an update of assitent previous 1.2.3 and I have updated it. THANK YOU VERY MUCH FOR YOUR HEL

Nice to see your issue has been figured out. Should there is any further question, feel free to contact us.

Hi Guys, I took your suggestion KedDk and downgraded to 1.2.3. and it worked fine. Susan I just tried to upload the log file but the program hung. Thanks for all your help.

Hiii SUSAN ....
i am facing some major issue with my both Pantom 4 and Pro. recently i have installed the latest firmware as it was asking for the installation but now i am not able to connect with any Third party application like litchi , ultimate.  It is continuously showing "Disconnected "  and not acquiring Satellite and not showing Current Location of the Drone.
And now i am not able to Downgrade the Current Firmware even with Assistant 2.

Please help...