classes set undefined on compile build

[RobertoGDev]

I say, I´m going to try the issues system of github! that I never tried this.
Ok , how I was saying, when compiles the project, the js file set the classes to "undefined". I think that can be a loader´s issue, but I can´t fix this.
I have an awesome english right? XDD

Here leave a screenshot that I expect could help you!

Regards