Angular 2 RC 5 - Can't bind to '…' since it isn't a known property of '…'

Question

Since the update to Angular 2 RC 5 I issue some problems. I have 3 components (battery, signal and maps) that are used in another component. These 3 components are declared in one module: the helpers module. Here is the code:

@NgModule({
    declarations: [
        SignalComponent,
        BatteryComponent,
        MapsComponent
    ],
    imports : [
        BrowserModule,
        FormsModule
    ],
    exports: [
        SignalComponent,
        BatteryComponent,
        MapsComponent
    ]
})
export class HelpersModule {
}

The battery component looks like this:

@Component({
    selector: 'as-my-battery',
    template: `
        <i class="fa fa-{{icon}}" aria-hidden="true"></i>
        `
})

export class BatteryComponent {
    @Input() level: number;
    @Output() icon: string;
    // constructor() { }

    ngOnInit () {
        if (this.level < 5) {
            this.icon = 'battery-empty';
        } else if (this.level >= 5 && this.level < 25) {
            this.icon = 'battery-quarter';
        } else if (this.level >= 25 && this.level < 50) {
            this.icon = 'battery-half';
        } else if (this.level >= 50 && this.level < 75) {
            this.icon = 'battery-three-quarters';
        } else {
            this.icon = 'battery-full';
        }
    }
}

But when I try to use the as-my-battery with the input level, I get this error:

Error: Uncaught (in promise): Template parse errors:
Can't bind to 'level' since it isn't a known property of 'as-my-battery'.
1. If 'as-my-battery' is an Angular component and it has 'level' input, then verify that it is part of this module.
2. If 'as-my-battery' is a Web Component then add "CUSTOM_ELEMENTS_SCHEMA" to the '@NgModule.schema' of this component to suppress this message.
 (""checkbox" name={{data.name}} value={{data.name}}> {{data.name}}
                    <as-my-battery [ERROR ->][level]='data.battery'></as-my-battery>
                    <as-my-signal [level]='data.signal'></as-"): a@19:35

Has someone else these issues, and eventually a solution for this problem?

I also found this topic, but that wasn't an answer for me: Can't bind to 'data' since it isn't a known property of 'teach-data'

And at last, this is the bootstrap of my app:

@NgModule({
    declarations: [
        AppComponent
    ],
    imports: [
        NavbarModule,
        LoginModule,
        HelpersModule,
        KaartModule,
        LijstModule,
        LogsModule,
        InstellingenModule,
        StatistiekenModule,
        routing
    ],
    providers: [ APP_PROVIDERS, appRoutingProviders ],
    bootstrap: [ AppComponent ]
})
export class AppModule {
}

The battery component needs to be used in the LijstComponent, declaration of the module:

@NgModule({
    declarations: [
        LijstComponent
    ],
    imports: [
        BrowserModule,
        HelpersModule
    ],
    exports: [
        LijstComponent
    ]
})
export class LijstModule {
}

The LijstComponent:

@Component({
    selector: 'as-lijst',
    providers: [DataService, MarkerService, AlertService],
    templateUrl: 'app/lijst/lijst.html',
})

export class LijstComponent {
...
}

And a snippet of the html (data is a *ngFor that is looping):

<as-my-battery [level]='data.battery'></as-my-battery>

Answer 1

I founded the solution, the problem lies with the uglify option of gulp. When setting the mangle option to false (in config.js), the app build and the error has gone!