If you find your hex file no longer works with your micro:bit and you see an error code on the screen or a FAIL.TXT on the MICROBIT drive, it could be because modifications have been made to the software that supports the device. 


Try updating your .hex file. by dragging it into the online editor that was used to create it and download it again.


A downloaded .hex file will now use the Universal Hex file format, designed to support all micro:bit versions. As such, the resultant file will be ~1.8Mb rather than ~600Kb


MakeCode Editor

  1. Drag the .Hex file you wish to update into the editor at makecode.microbit.org
  2. Choose Download to compile the file and save it.


Python Editor

  1. Drag the .Hex file you wish to update into the editor at python.microbit.org
  2. Choose Download to compile the file and save it.




If that doesn’t resolve the issue, please open a support ticket



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