Are you on Mac OS? Please could you try uploading firmware using the instructions at http://www.espruino.com/MDBT42Q#firmware-updates (so using the nRF Connect app on Android/iOS instead)
@Gordon started
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
Are you on Mac OS? Please could you try uploading firmware using the instructions at http://www.espruino.com/MDBT42Q#firmware-updates (so using the nRF Connect app on Android/iOS instead)