Starting grunt server via: grunt serve and got following error
Loading "connect_proxy.js" tasks...ERROR >> TypeError: Cannot read property 'prototype' of undefined
The issue seems already raised on grunt-connect-proxy module already and it has already fixed for the new version, if you still face the error above, please try following command to solve it:
rm -rf node_modules/grunt-connect-proxy npm install eventemitter3@0.1.6 npm install grunt-connect-proxy
It is because of the dependency: eventemitter3 that from version 0.1.6, it has been solved already, please use latest one.