title: Angular 2 - Error when I execute ng build --prod
body: <p>I'm using angular cli to create my angular projects 2.</p>
  
  <p>I had no problem in developing. I always executed npm start and never had error.</p>
  
  <p>However I went to run the command: ng build --prod and he angular cli presented me with several errors.</p>
  
  <p>Errors of type:</p>
  
  <p>That I should declare the variable as public to use in my html, A property did not exist in the class and others.</p>
  
  <p>I do not understand the reason Angular cli not having warned before. Now there are more than 200 errors. </p>
  
  <p>Does anyone know why angular cli have not caught these errors before? Is there any solution for this?</p>