error NG6002：出现在AppModule的NgModule.imports中，但本身有错误

Question

I am having angular 12 in my local and building project which runs fine without any error.

My local setup:

Angular CLI: 12.0.5  
Node: 12.16.3  
Package Manager: npm 6.14.4  
OS: win32 x64  
Angular: 12.0.5

But while building my project on the linux server it is giving this error with nothing much to work with.

Server setup:

Angular CLI: 12.0.5  
Node: 14.18.1  
Package Manager: npm 6.14.15  
OS: linux x64  
Angular: 12.0.5

Error: src/app/app-routing.module.ts:34:14 - error NG6002: Appears in the NgModule.imports of AppModule, but itself has errors  
34 export class AppRoutingModule { }

app.module.ts

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';

import { AppRoutingModule } from './app-routing.module';
import { AppComponent } from './app.component';
import { HomeComponent } from './home/home.component';
import { HeaderComponent } from './header/header.component';
import { FooterComponent } from './footer/footer.component';
import { NotifyFormComponent } from './notify-form/notify-form.component';
import { LoginComponent } from './login/login.component';

@NgModule({
  declarations: [
    AppComponent,
    HomeComponent,
    HeaderComponent,
    FooterComponent,
    NotifyFormComponent,
    LoginComponent
  ],
  imports: [
    AppRoutingModule,
    BrowserModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

app-routing.module.ts

import { LoginComponent } from './login/login.component';
import { NgModule } from '@angular/core';
import { RouterModule, Routes } from '@angular/router';
import { NotifyFormComponent } from './notify-form/notify-form.component';
import { HomeComponent } from './home/home.component';

const routes: Routes = [
  {path:'',redirectTo:'/',pathMatch: 'full'},
  {
    path:'', 
    component: HomeComponent,
    children:[
      
    ]
  },
  {
    path:'notify', 
    component: NotifyFormComponent
  },
  {
    path:'login', 
    component: LoginComponent
  }
  // {
  //   path:'**', 
  //   component: HomeComponent
  // }
];

@NgModule({
  imports: [RouterModule.forRoot(routes)],
  exports: [RouterModule]
})
export class AppRoutingModule { }

tsconfig.json

{
  "compileOnSave": false,
  "compilerOptions": {
    "baseUrl": "./",
    "outDir": "./dist/out-tsc",
    "forceConsistentCasingInFileNames": true,
    "strict": true,
    "noImplicitReturns": true,
    "noFallthroughCasesInSwitch": true,
    "sourceMap": true,
    "declaration": false,
    "downlevelIteration": true,
    "experimentalDecorators": true,
    "moduleResolution": "node",
    "importHelpers": true,
    "target": "es2017",
    "module": "es2020",
    "lib": [
      "es2018",
      "dom"
    ]
  },
  "angularCompilerOptions": {
    "enableI18nLegacyMessageIdFormat": false,
    "strictInjectionParameters": true,
    "strictInputAccessModifiers": true,
    "strictTemplates": true
  }
}

Please help me if I am doing anything horribly wrong here. It is just a simple project to test with. Thanks a lot in advance.

Answer 1

I went on a bit of a research spree and here's an official issue for it https://github.com/angular/angular/issues/35399 . Also here's another question for it error NG6002: Appears in the NgModule.imports of AppModule, but could not be resolved to an NgModule class . But I'll go ahead and summarize things I've found anyways.

• For many people it worked simply restarting and rebuilding the project, or doing a full forced npm cache clear and reinstalling node_modules and rebuilding it.

• People have suggested disabling "ivy" in tsconfig works, however it's also been mentioned that while it works it's not the recommended way of fixing it.

• This can apparently also happen if you've added components to imports instead of declarations.

• This can apparently also happen if you've installed some packages as root or if you for some reason don't have permissions on all the packages. Which was fixed with doing a chown on the directory, however the real solution is to install packages correctly in the first place and configuring the npm config so you don't ever install packages with root permissions. So essentially if you installed packages with root and try and run the project as non root, it will give this issue.

• Some people got the error when they added a service to imports instead of providers.

• People also get this error if they name the package incorrectly ie SomeComponent instead of SomeComponentModule.

• In your specific case, you've imported the app router before browser module, I have no idea if that could cause an issue but everywhere I've seen the browser module is added before the app, so swap them around if nothing else work and see if that works.

That's about everything I could find.

Answer 2

您必须检查是否将所需的所有内容导入 app.module.ts，然后检查 linux 也许您需要添加任何其他组件，但这样应该可以正常工作

Answer 3

尝试 npm 版本应该 > 8.1.0 并且节点版本应该 > v16.13.0

Answer 4

I had this issue when I transferred a project from Windows to Linux.
The paths on the imports for my modules had capital letters and this failed in linux and worked in windows.
For example either of the following will work on Windows:

import { switchMap, tap } from 'rxjs/operators';
import { switchMap, tap } from 'rxjs/Operators';

On Linux only the lower case version will work:

import { switchMap, tap } from 'rxjs/operators';

Answer 5

我用ng serve命令解决了这个问题。当您更改 angular.json 文件中的配置时，您会遇到这个问题。

Answer 6

check if the paths mentioned in 'templateUrl' and 'styleUrls' are correct in the components wich are related to this module who has a problem,

@Component({
    selector: 'app-navigation-menu-item',
    templateUrl: './xxx.component.html',
    styleUrls: ['./xxx.component.scss']
})

in my case, this was the bug.