Uncaught Error: No template specified for component MyApp

I had the same problem and what was causing was a commented line. I suggest that answer even if you didn't include a commented line in your example (I supposed that you didn't imagine that a commented line could cause the error). The following produced the same error as you :

@Component({
    //template: `<ion-nav [root]="rootPage"></ion-nav>`  
    templateUrl: 'app.html'
})

I had to do the following change for the compilation to work (while using ionic-app-scripts @ 0.0.30, I have the feeling that the problem appeard between v0.0.23 and v0.0.30, but I didn't investigate) :

@Component({
  templateUrl: 'app.html'
  //template: `<ion-nav [root]="rootPage"></ion-nav>`
})

In layman terms, in your component.ts file add templateURL. Follow the code snippet as follows :-

@Component({
  selector: 'app-securelogin-receiver',
  templateUrl: './securelogin-receiver.component.html',
  providers: [SecureloginService]
})

Which is being referred at the time of component load, hence its unavailability throws exception.

Error: No template specified for component SecureloginReceiverComponent

above exception i got in templateURL's absence.