NullInjectorError: No provider for t! NullInjectorError: StaticInjectorError(ba)[Cw -> t]:

When I run my prod build of my Angular 8 app, I am getting this error in console. The build runs fine and I've included all services in my provider.

I've run the following commands but do not get any errors. ng build --prod --optimization=false Is there any way to tell what is failing? Even when I comment out all the providers (expecting the build the fail), I still receive no errors.

Please let me know what other information I can/should provide for your help. Thanks!

error message:

app.module.ts

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
import { FormsModule, ReactiveFormsModule } from '@angular/forms';

import { HttpClientModule, HTTP_INTERCEPTORS, HttpClient } from '@angular/common/http';
import { RouterModule } from '@angular/router';
import { AppComponent } from './app.component';
import { HomeComponent } from './home/home.component';
import { NavMenuComponent } from './nav-menu/nav-menu.component';

//a bunch more components...

import { AccountModule } from './account/account.module';
import { AccountRoutingModule } from './account/account.routing.module';
import { AuthGuard } from './helpers/auth.guard';
import { ErrorInterceptor } from './helpers/error.interceptor';
import { JwtInterceptor } from './helpers/jwt.interceptor';

import { TemplateService } from './services/template.service';
import { ExerciseService } from './services/exercise.service';
import { ExamService } from './services/exam.service';
import { AuthService } from './services/auth.service';
import { FeatureService } from './services/feature.service';
import { RoleService } from './services/role.service';
import { UserService } from './services/user.service';

@NgModule({
  declarations: [
    AppComponent,
    NavMenuComponent,
    HomeComponent,

  ],
  imports: [
    BrowserModule.withServerTransition({ appId: 'ng-cli-universal' }),
    HttpClientModule,
    FormsModule,
    ReactiveFormsModule,
    BrowserAnimationsModule,
    AccountModule,
    AccountRoutingModule,
    RouterModule.forRoot([
      { path: '', component: HomeComponent, canActivate: [AuthGuard] },
      //all routes left out for brevity
    ])
  ],
  //entryComponents: [NewTemplateModal, NewExerciseModal, AddFeaturesModal, SaveSuccessComponent, ErrorComponent],
  providers: [    
    AuthService,
    ExamService,
    ExerciseService,
    FeatureService,
    RoleService,
    TemplateService,
    UserService,
    HttpClient,
    { provide: HTTP_INTERCEPTORS, useClass: ErrorInterceptor, multi: true },
    { provide: HTTP_INTERCEPTORS, useClass: JwtInterceptor, multi: true },
  ],
  bootstrap: [AppComponent]
})
export class AppModule { }

build:

Turns out it was something stupid...

In one of my components I had providers:[]. Once I removed that completely it started working.

Hope this can help someone else!