If you find your hex file no longer works with your micro:bit, it could be because modifications have been made to the underlying software that supports the device. 


Try updating your .hex file. which is simply a case of dragging it into the online editor that was used to create it and re-download it.


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



Additional keywords for search: updating hex, universal hex, hex file is 1.8mb, 600kb, hex file is double in size