@Mael_Forestal; Hello, I just found this PX4 Firmware problem here and I need your help…? I have a Holybro Pixhawk 4 Flight Controller for my Quadcopter. I was using Mission Planner bcuz… QGC had ton’s (844) issues a while back, I didn’t want any Problems…! Some how Mission Planner put “Ardupilot ChibiOS” on my PX 4 board… Now when I try to update firmware in QGC…when it connects to F/C it shows, “found ardupilot chibiOS” “connected to bootloader” and QGC shows “erasing” Copying files, program complete…! If I go back to Firmware again, it still shows “ardupilot chibiOS” as Bootloader… I need to know how you were able/Process for QGC to Flash the ([http://px4-travis.s3.amazonaws.com/Firmware/stable/px4fmu-v5_default.px4… to your px4…? =) Thanks in Advance…! =) James…