Usually, this means that your computer is not able to provide enough power to JeVois.
Thanks for mentioning that you are using a surface pro (tablet), this could be the problem.
Have a look here:
http://jevois.org/doc/UserConnect.html
You may need to supplement the current that the tablet can provide, by using a Y cable, and connecting the power end of it either to a battery or a phone charger.