I think most likely what you did (whether you intended to or not) is uploaded the Web IDE's default flashing light example to flash memory, which overwrote the bootloader.
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.
I think most likely what you did (whether you intended to or not) is uploaded the Web IDE's default flashing light example to flash memory, which overwrote the bootloader.
Glad you got it solved by updating it :)