DJI firmware update error: fixes for failed or stuck updates

A DJI firmware update usually fails for one of three reasons, according to DJI: a battery below 50% that shuts down mid-update, someone touching the drone or unplugging a cable during the update, or a network or download problem on the phone. Charge the drone and controller above 50%, keep the phone online and leave everything alone until the drone restarts. If the app keeps failing, update with DJI Assistant 2 on a computer instead.

Before a DJI firmware update — DJI's help center says most failed updates come from low battery, interrupting the update, or a network problem. The Mini 4 Pro manual gives the 10-minute estimate.

Fixes, in order

Charge up. DJI's help center asks for more than 50% on both the drone and the controller. The Mini 4 Pro manual sets a minimum of 40% for the flight battery and 20% for the controller; aim higher.
Stay online. DJI Fly downloads the firmware before installing it. Use a strong Wi-Fi connection, and keep DJI Fly open.
Link first. DJI's Mini 4 Pro manual says you can't update if the controller isn't linked to the drone.
Don't interrupt it. Don't power anything off or unplug the USB cable. On the Mini 4 Pro, DJI says the update takes about 10 minutes and it's normal for the gimbal to go limp, the status lights to blink and the drone to reboot.
If the progress bar is stuck for a long time, restart the drone, controller and phone, and try again.
Try a different phone. DJI suggests switching between iPhone and Android if downloads keep failing, using a phone on its compatibility list.
Use DJI Assistant 2. Connect the powered-on drone to a computer by USB, open the Consumer Drones Series edition, sign in, select the device and choose Firmware Update. Update the drone and controller separately. See DJI Assistant 2 not detecting your drone if it won't connect.

"Inconsistent firmware" and battery updates

DJI's manuals say the battery firmware is included in the drone's firmware, so every battery needs to be inserted and updated. If DJI Fly shows "Inconsistent firmware found", or a battery has LED 2 and LED 3 lit steadily, DJI says the battery's update failed. Put that battery in the drone, connect to DJI Fly and accept the update. If no prompt appears, use DJI Assistant 2. DJI asks for more than 75% charge before retrying a failed battery update. See DJI battery error.

Mini 3 Pro firmware not installing

The Mini 3 Pro updates the same way. If DJI Fly downloads but won't install:

Charge the drone and the DJI RC or RC-N1 above 50%.
On the DJI RC, update the controller first when DJI Fly offers it; a solid yellow status LED on the DJI RC means a failed update.
Restart all devices, then retry.
If it still fails, use DJI Assistant 2 (Consumer Drones Series).

Controller and goggles

Screen controllers like the DJI RC 2 update over Wi-Fi in DJI Fly. Goggles update through DJI Fly on a connected phone or through DJI Assistant 2. Keep each device charged above 50% while it updates.

When to contact DJI

Take a screenshot of the error and contact DJI Support if updates fail in both DJI Fly and DJI Assistant 2. A drone that won't power off after a failed update is a known DJI case that needs service. For device-by-device steps, including DJI Mic and Neo, read DJI firmware update failed or stuck and how to update DJI firmware.