AREDN gurus, this newby is stuck. So I'm attempting to flash a Rocket M5 -- my third experience in doing this (it does get easier). The unit accepted the downgrade to AirOS to 5.5.10, and the U-Boot test gave me two GREENs. All is well. I call up the file AREDN-3.16.1.1-ubnt-rocket-m-squashfs-factory.bin and upload to AirOS, which returns an error message: "Firmware image check failed. Error Code -6" I re-downloaded the files several times -- same result. I even re-flashed the unit back up to 5.6 and then flashed again downgrading to 5.5. Same result. Any guesses please?