Microbit v.2.21 error code 528

i ve just got a microbit v2.21 new one but it shows error code 528 and i tried to upgrade or downgrade with maintanence mode but not successfull any idea ? what should i do ?

Error 528 looks to be a flashing error - the troubleshooting suggests:

The micro:bit has detected an unsupported update. This can occur if you attempt to flash a firmware .hex file whilst in normal MICROBIT mode. Try flashing a file created in one of the online editors to resolve the issue.