error NG6002: Appears in the NgModule.imports of AppModule, but could not be resolved to an NgModule class. Is it missing an @NgModule annotation?

Question

I am getting this error in my super simple Angular app and I do not know why I am getting this error. I a providing a screenshot that should answer most questions you might have.

error NG6002: Appears in the NgModule.imports of AppModule, but could not be 
  resolved to an NgModule class.
    Is it missing an @NgModule annotation?

NOTE: When I first generated the ChannelService class, it was compiling, but stopped working after I fiddled around with it. I tried the obvious things like deleting node_modules and rebuilding.

Answer 1

You have a service in your module imports, it is a provider and should be automatically registered because it is providedIn: 'root'

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    HttpClientModule,
    ChannelService, // <-- remove this
    BrowserModule,
    AgGridModule.withComponents([])
  ],
  providers: [],
  bootstrap: [AppComponent]
})