Angular 6 Application Productions build gets successfully but on load throws error No component factory found for t

you have some components injected or used in other components so if you are using lazy loading modules then you need to add it to entrycomponents array in the parent lazy loaded module, if not then you need to add it to app module.

also make sure that all entry components added to declaration array.

@NgModule({
  declarations: [
    AppComponent,
    YourComponent
  ],
  imports: [
    BrowserModule,
    FormsModule,
    HttpClientModule,
    AppRoutingModule
  ],
  providers: [],
  entryComponents: [YourComponent]
  bootstrap: [AppComponent]
})

if your entry component in another module, you should export it there first to use it.

exports: [ YourComponent ]

that issue happens alot specially when you use components as popups or dialogs