Problem: Upgrading to the latest Ardupilot FW 4.1.0 on Matek F405 - Wing

I have a Matek-F405 wing running on 3.9.11 Arduplane FW and I am trying to upgrade this board with 4.1.0 latest release by “Custom FW load” feature on the MP (lower right on MP). Its giving me an error.

Can someone explain the right way to do this or should I just use 4.0.6 currently on the MP?

Download the .apj file from here and use the Custom firmware load to install it.

I must ask, what is apj extension file?

Pre-built firmware that can be loaded from A GCS. ArduPilot Json I suppose.

Thank you Dave. apj extensions are for AutoCad file type typically used in architecture :wink: