I think it's possible you could reduce the amount of jsvars available in boards/ESP8266_BOARD.py as it may be running out of RAM...
boards/ESP8266_BOARD.py
@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.
I think it's possible you could reduce the amount of jsvars available in
boards/ESP8266_BOARD.py
as it may be running out of RAM...