Having trouble to connect after loading new plan

Hi I am still new to autopilots.

I have an old pixfalcon that had the ardurover firmware on it used alot and was working perfectly.

After loading a new plan today the autopilot start flashing and al of a sudden the main Led light is not working anymore and my pc is also not detecting the device anymore tried changing ports and cables nothing works.

The FMR B/E light is on and the pwr light is on and is green.

I have tried holding in the reset button then powering on but does not change anything.

Even formatted the sd Card but nothing changed.

Thank for the help in advance.

Use QGroundControl to update the firmware, after that you can go back to MissionPlanner

Thank you I have tried Qgroundcontrol but nothing changed my pc does not detect my autopilot anymore for some reason and just a few minutes before it worked perfectly.