The firmware expects a parameter that is not in this build

What ArduPilot says:

• Config Error: param deflt fail:…

During start-up the vehicle code gives some parameters its own defaults by name. Here the named parameter does not exist in this firmware, which means a piece of code the vehicle needs was left out of the build. It is a configuration error: the board repeats “Config Error: param deflt fail:NAME” and does not finish starting.

What to do, most likely first

1. A custom build left out a feature that this vehicle type needs.

   CheckThe name after the colon tells which feature: look the parameter up, and see in the Firmware Inspector whether that feature is in the file you flashed.

   FixBuild again with the feature included, or flash the official firmware for your board.

Where to do it:Firmware BuilderFirmware InspectorSetup & Tuning Guide