I had the same issue since I tried using the espruino_2v04.399_banglejs.zip firmware which was in http://www.espruino.com/binaries/travis/master/. But using espruino_2v04_banglejs.zip firmware from http://www.espruino.com/binaries/travis/cad1b987f8c6a3af1fcc6984980f4023c4732aca/ worked.
@labarks 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 had the same issue since I tried using the espruino_2v04.399_banglejs.zip firmware which was in http://www.espruino.com/binaries/travis/master/.
But using espruino_2v04_banglejs.zip firmware from http://www.espruino.com/binaries/travis/cad1b987f8c6a3af1fcc6984980f4023c4732aca/ worked.