Error: you must specify the protocol for the proxy type

Ionic Framework ionic-v3
1

Hi guys, I’ve been getting the follow error, when I try to start a new project.Then I tried to figure out how to solve the problem, but there is no answer for it, please guys help me!

TypeError: You must specify a "protocol" for the proxy type (http, https, socks, socks4, socks4a, socks5, socks5h, pac+data, pac+file, pac+ftp, pac+http, pac+https)
    at mapOptsToProxy (C:\Users\usuario\AppData\Roaming\npm\node_modules\@ionic\cli-plugin-proxy\node_modules\proxy-agent\index.js:100:11)
    at new ProxyAgent (C:\Users\usuario\AppData\Roaming\npm\node_modules\@ionic\cli-plugin-proxy\node_modules\proxy-agent\index.js:150:17)
    at ProxyAgent (C:\Users\usuario\AppData\Roaming\npm\node_modules\@ionic\cli-plugin-proxy\node_modules\proxy-agent\index.js:145:45)
    at Request.proxy (C:\Users\usuario\AppData\Roaming\npm\node_modules\@ionic\cli-plugin-proxy\node_modules\superagent-proxy\index.js:71:15)
    at C:\Users\usuario\AppData\Roaming\npm\node_modules\ionic\node_modules\@ionic\cli-utils\lib\http.js:46:17
    at Generator.next (<anonymous>)
    at fulfilled (C:\Users\usuario\AppData\Roaming\npm\node_modules\ionic\node_modules\tslib\tslib.js:104:62)
2

This might help :
http://jasonwatmore.com/post/2014/04/02/ionic-framework-getting-ionic-start-appname-working-behind-a-proxy