Can you use the version of the Web IDE from here instructions are on that page. You should them be able to right-click in the window and click 'inspect element', followed by 'Console'.
Then, when you click the 'send to espruino' button you should be able to see if the Web IDE is having any issues...
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.
Can you use the version of the Web IDE from here instructions are on that page. You should them be able to right-click in the window and click 'inspect element', followed by 'Console'.
Then, when you click the 'send to espruino' button you should be able to see if the Web IDE is having any issues...