error NG6002: Appears in the NgModule.imports of AppModule, but could not be resolved to an NgModule class

Question

First time using firestore and I\'m getting this error. It seems to be a problem with Ivy, from my research. I don\'t have a lot of experience modifying tsconfig.app.json, w

Answer 1

I got this error when I added the service class. I was using Angular 9 Went for several solutions, nothing helped me to resolve this issue. If U tried everything make sure u added ng module reference in core lib inside service. See Img

Answer 2

Restarting your server may not work always. I have got this error when I imported MatFormFieldModule.

In app.module.ts, I have imported MatFormField instead of MatFormFieldModule which lead to this error.

Now change it and restart the server, Hope this answer helps you.

Answer 3

I have faced the same issue in Ubuntu because the Angular app directory was having root permission. Changing the ownership to the local user solved the issue for me.

$ sudo -i
$ chown -R <username>:<group> <ANGULAR_APP>
$ exit 
$ cd <ANGULAR_APP>
$ ng serve

Answer 4

This issue will be fixed by adding the postinstall script below in your package.json.

It will be run after a npm install.

"scripts": {
   "postinstall": "ngcc"
}

Post adding the above code, run npm install

This works for me when upgrading to Angular 9+

Answer 5

This error shows when you add component declaration in imports: [] instead of declarations: [], e.g:

declarations: [
  AppComponent,
],
imports: [
  BrowserModule,
  AppRoutingModule,
  SomeComponent <-----------wrong
],

Answer 6

In Your "tsconfig.app.json" Add Following Lines

"angularCompilerOptions": { "enableIvy": false }

Where to add? Just After Following Lines Of Code "exclude": ["src/test.ts", "src/**/*.spec.ts"],