Angular 6 - Could not find module "@angular-devkit/build-angular"

Question

After updating to Angular 6.0.1, I get the following error on ng serve:

Could not find module "@angular-devkit/build-angular" from "/home/Projects/myProjectName".
Error: Could not find module "@angular-devkit/build-angular" from "/home/Projects/myProjectName".
    at Object.resolve (/home/Projects/myProjectName/node_modules/@angular-devkit/core/node/resolve.js:141:11)
    at Observable.rxjs_1.Observable [as _subscribe] (/home/Projects/myProjectName/node_modules/@angular-devkit/architect/src/architect.js:132:40)

ng update says everything is in order. Deleting the node_modules folder and a fresh npm install install did not help either.

My project is based on ng2-admin (Angular 4 version). Here are my package.json dependencies:

 "dependencies": {
    "@angular/animations": "^6.0.1",
    "@angular/common": "^6.0.1",
    "@angular/compiler": "^6.0.1",
    "@angular/core": "^6.0.1",
    "@angular/forms": "^6.0.1",
    "@angular/http": "^6.0.1",
    "@angular/platform-browser": "^6.0.1",
    "@angular/platform-browser-dynamic": "^6.0.1",
    "@angular/platform-server": "^6.0.1",
    "@angular/router": "^6.0.1",
    "@ng-bootstrap/ng-bootstrap": "1.0.0-alpha.26",
    "@ngx-translate/core": "^10.0.1",
    "@ngx-translate/http-loader": "^3.0.1",
    "amcharts3": "github:amcharts/amcharts3",
    "ammap3": "github:amcharts/ammap3",
    "angular-table": "^1.0.4",
    "angular2-csv": "^0.2.5",
    "angular2-datatable": "0.6.0",
    "animate.css": "3.5.2",
    "bootstrap": "4.0.0-alpha.6",
    "bower": "^1.8.4",
    "chart.js": "1.1.1",
    "chartist": "0.10.1",
    "chroma-js": "1.3.3",
    "ckeditor": "4.6.2",
    "core-js": "2.4.1",
    "easy-pie-chart": "2.1.7",
    "font-awesome": "4.7.0",
    "fullcalendar": "3.3.1",
    "google-maps": "3.2.1",
    "ionicons": "2.0.1",
    "jquery": "3.2.1",
    "jquery-slimscroll": "1.3.8",
    "leaflet": "0.7.7",
    "leaflet-map": "0.2.1",
    "lodash": "4.17.4",
    "ng2-ckeditor": "1.1.6",
    "ng2-completer": "^1.6.3",
    "ng2-handsontable": "^2.1.0-rc.3",
    "ng2-slim-loading-bar": "^4.0.0",
    "ng2-smart-table": "^1.0.3",
    "ng2-tree": "2.0.0-alpha.5",
    "ngx-uploader": "4.2.4",
    "normalize.css": "6.0.0",
    "roboto-fontface": "0.7.0",
    "rxjs": "^6.1.0",
    "rxjs-compat": "^6.1.0",
    "zone.js": "0.8.26"
  },
  "devDependencies": {
    "@angular/cli": "^6.0.1",
    "@angular/compiler-cli": "^6.0.1",
    "@types/fullcalendar": "2.7.40",
    "@types/jasmine": "2.5.38",
    "@types/jquery": "2.0.41",
    "@types/jquery.slimscroll": "1.3.30",
    "@types/lodash": "4.14.61",
    "@types/node": "6.0.69",
    "codelyzer": "3.0.1",
    "gh-pages": "0.12.0",
    "jasmine-core": "2.5.2",
    "jasmine-spec-reporter": "3.2.0",
    "karma": "1.4.1",
    "karma-chrome-launcher": "2.0.0",
    "karma-cli": "1.0.1",
    "karma-coverage-istanbul-reporter": "0.2.0",
    "karma-jasmine": "1.1.0",
    "karma-jasmine-html-reporter": "0.2.2",
    "npm-run-all": "4.0.2",
    "protractor": "5.1.0",
    "rimraf": "2.6.1",
    "standard-changelog": "1.0.1",
    "stylelint": "7.10.1",
    "ts-node": "2.1.2",
    "tslint": "5.2.0",
    "tslint-eslint-rules": "4.0.0",
    "tslint-language-service": "0.9.6",
    "typescript": "^2.7.2",
    "typogr": "0.6.6",
    "underscore": "1.8.3",
    "wintersmith": "2.2.5",
    "wintersmith-sassy": "1.1.0"
  }

And my angular.json file:

{
  "$schema": "./node_modules/@angular/cli/lib/config/schema.json",
  "version": 1,
  "newProjectRoot": "projects",
  "projects": {
    "ng2-admin": {
      "root": "",
      "sourceRoot": "src",
      "projectType": "application",
      "architect": {
        "build": {
          "builder": "@angular-devkit/build-angular:browser",
          "options": {
            "outputPath": "dist",
            "index": "src/index.html",
            "main": "src/main.ts",
            "tsConfig": "src/tsconfig.app.json",
            "polyfills": "src/polyfills.ts",
            "assets": [
              "src/assets",
              "src/favicon.ico"
            ],
            "styles": [
              "node_modules/roboto-fontface/css/roboto/sass/roboto-fontface.scss",
              "node_modules/normalize.css/normalize.css",
              "node_modules/font-awesome/scss/font-awesome.scss",
              "node_modules/ionicons/scss/ionicons.scss",
              "node_modules/bootstrap/scss/bootstrap.scss",
              "node_modules/leaflet/dist/leaflet.css",
              "node_modules/chartist/dist/chartist.css",
              "node_modules/fullcalendar/dist/fullcalendar.css",
              "node_modules/handsontable/dist/handsontable.full.css",
              "node_modules/ng2-slim-loading-bar/style.css",
              "src/app/theme/theme.scss",
              "src/styles.scss"
            ],
            "scripts": [
              "node_modules/jquery/dist/jquery.js",
              "node_modules/easy-pie-chart/dist/jquery.easypiechart.js",
              "node_modules/jquery-slimscroll/jquery.slimscroll.js",
              "node_modules/tether/dist/js/tether.js",
              "node_modules/bootstrap/dist/js/bootstrap.js",
              "node_modules/handsontable/dist/handsontable.full.js",
              "node_modules/chroma-js/chroma.js"
            ]
          },
          "configurations": {
            "production": {
              "optimization": true,
              "outputHashing": "all",
              "sourceMap": false,
              "extractCss": true,
              "namedChunks": false,
              "aot": true,
              "extractLicenses": true,
              "vendorChunk": false,
              "buildOptimizer": true,
              "fileReplacements": [
                {
                  "replace": "src/environments/environment.ts",
                  "with": "src/environments/environment.prod.ts"
                }
              ]
            }
          }
        },
        "serve": {
          "builder": "@angular-devkit/build-angular:dev-server",
          "options": {
            "browserTarget": "ng2-admin:build"
          },
          "configurations": {
            "production": {
              "browserTarget": "ng2-admin:build:production"
            }
          }
        },
        "extract-i18n": {
          "builder": "@angular-devkit/build-angular:extract-i18n",
          "options": {
            "browserTarget": "ng2-admin:build"
          }
        },
        "test": {
          "builder": "@angular-devkit/build-angular:karma",
          "options": {
            "main": "src/test.ts",
            "karmaConfig": "./karma.conf.js",
            "polyfills": "src/polyfills.ts",
            "tsConfig": "src/tsconfig.spec.json",
            "scripts": [
              "node_modules/jquery/dist/jquery.js",
              "node_modules/easy-pie-chart/dist/jquery.easypiechart.js",
              "node_modules/jquery-slimscroll/jquery.slimscroll.js",
              "node_modules/tether/dist/js/tether.js",
              "node_modules/bootstrap/dist/js/bootstrap.js",
              "node_modules/handsontable/dist/handsontable.full.js",
              "node_modules/chroma-js/chroma.js"
            ],
            "styles": [
              "node_modules/roboto-fontface/css/roboto/sass/roboto-fontface.scss",
              "node_modules/normalize.css/normalize.css",
              "node_modules/font-awesome/scss/font-awesome.scss",
              "node_modules/ionicons/scss/ionicons.scss",
              "node_modules/bootstrap/scss/bootstrap.scss",
              "node_modules/leaflet/dist/leaflet.css",
              "node_modules/chartist/dist/chartist.css",
              "node_modules/fullcalendar/dist/fullcalendar.css",
              "node_modules/handsontable/dist/handsontable.full.css",
              "node_modules/ng2-slim-loading-bar/style.css",
              "src/app/theme/theme.scss",
              "src/styles.scss"
            ],
            "assets": [
              "src/assets",
              "src/favicon.ico"
            ]
          }
        },
        "lint": {
          "builder": "@angular-devkit/build-angular:tslint",
          "options": {
            "tsConfig": [
              "src/tsconfig.app.json",
              "src/tsconfig.spec.json"
            ],
            "exclude": []
          }
        }
      }
    },
    "ng2-admin-e2e": {
      "root": "",
      "sourceRoot": "",
      "projectType": "application",
      "architect": {
        "e2e": {
          "builder": "@angular-devkit/build-angular:protractor",
          "options": {
            "protractorConfig": "./protractor.conf.js",
            "devServerTarget": "ng2-admin:serve"
          }
        },
        "lint": {
          "builder": "@angular-devkit/build-angular:tslint",
          "options": {
            "tsConfig": [
              "e2e/tsconfig.e2e.json"
            ],
            "exclude": []
          }
        }
      }
    }
  },
  "defaultProject": "ng2-admin",
  "schematics": {
    "@schematics/angular:component": {
      "prefix": "app",
      "styleext": "scss"
    },
    "@schematics/angular:directive": {
      "prefix": "app"
    }
  }
}

Definite

I deleted the node_modules and package-lock.json folders and then typed npm i on the command line. After that, everything was fine. – Electrodialysis

sometimes, you might not have node_modules folder at all, maybe fresh clone. run npm install first. – Unbearable

Do you have folder node_modules ? For me the same error happened, when I cloned my Angular project through GitHub on different laptop. I didn't push folder node_modules to save space. Because I was on cell phone tethering, I decided do not reinstall all packages, but copy node_modules folder from different project on the same laptop. And it worked! – Polky

So many identical answers to this question. – Tetrabasic

@SteveSmith I've already flagged a few, but if you notice such answers in the future, you can custom flag them and leave a link to the original answer to get them cleaned up. – Bumptious

Hey everyone, if the below answers didn't work even after deleting npm_modules and reinstalling, try deleting package-lock.json and try npm install again. I ran into similar issue once and deleting package-lock.json and doing npm install worked for me back then. Hope this helps. – Ingemar

This one worked for me - https://mcmap.net/q/53492/-angular-6-could-not-find-module-quot-angular-devkit-build-angular-quot – Incubus

Answer 1

Install @angular-devkit/build-angular as dev dependency. This package is newly introduced in Angular 6.0

npm install --save-dev @angular-devkit/build-angular

or,

yarn add @angular-devkit/build-angular --dev

Function

Exact same error? And the configuration file? are they same as this question? – Function

Yes. Well, I did some more exploring on this issue. Turns out that it works fine on my Mac Mini, so it will probably has something to do with my Node setup on Windows. – Backlog

Then try to delete node_module folder & clean cache & install again – Function

Try to delete node_module & npm cache... @AmritaSrivastava – Function

hugo der hungrige here said: 1. Update all dependencies and make sure the app itself works as intented 2. Replace every occurrence of @angular/cli with @angular-devkit/build-angular in the karma.conf.js 3. Removing the files and the preprocessor configs from the karma.conf.js completely. This is all defined in the angular.json and should be handled automatically by the @angular-devkit karma plugin. Doing #3 worked for me – Autotrophic

Upgrade to angular 7 - the accepted answer fixed the error (have upvoted), but didn't solve the upgrade problem overall. This did https://mcmap.net/q/54736/-cannot-find-module-39-webpack-39-angular – Malevolent

Thanks for this. I just hit this problem while attempting to follow the Angular tutorial: angular.io/guide/quickstart - seems like someone forgot to update the documentation? – Occurrence

I don't know why its called devkit if we still need it on prod? – Conclave

This command is only making the situation bad by removing the angular devkit – Woodson

I had to run in adicional the following command: "npm audit fix --force" – Unhandy

Seems wonky that I have to execute this command every time I clear out node_modules/. – Millimicron

just try yarn or npm install – Rowley

This solution not work for me. if any other solution please update – Compte

Question though: if my package.json mentioned it needs this package as a dev dependency, why wouldn't NPM fetch it for me, transitively? Seems like a bad UX to me. – Jacksmelt

This issue might occur some times due to restricted environment also. check with IT team for angular repo setup internal. Most of the banking services companies will not accept public artifactories. – Kemme

Same error. Bad answer. – Balmacaan

I ran with this command: npm install --save-dev @angular-devkit/build-angular --force – Prinz

Answer 2

npm update

It worked like a charm.

Catenate

I moved to a new machine halfway through the angular-tour-of-heroes tutorial and pulled the half baked work from source control. This fixed it. – Allocation

Nothing "half baked" about not checking in the node modules folder. This simply rebuilds your node modules based on your package.json. This is perfectly normal thing to do when you check out a new solution. – Bereniceberenson

There might be additional packages that are outdated. Run ng update --all to try to update all at the same time. – Amygdalin

after i cloned my project in another machine i was having this issue, and this solution worked perfectly, thanks – Sowder

this should be the accepted answer. – Squall

Answer 3

For Angular 6 and above, the working solution for me was:

npm install

ng update

And finally

npm update

Inapprehensive

When I do the ng update I got several messages about several specific updates needed. Name Version Command to update -------------------------------------------------------------------------------- @angular/core 4.4.7 -> 8.2.4 ng update @angular/core @ngrx/store 2.2.3 -> 8.3.0 ng update @ngrx/store rxjs 5.5.12 -> 6.5.3 ng update rxjs – Stricker

npm i only without ng update and npm upsdate worked for me (Angular 12). Anyway thank you so much! – Marsh

noo doesnt work – Balmacaan

Answer 4

We need to explicitly get devDependencies.

npm i --only=dev

Shechem

This worked for me, same answer in: github.com/angular/angular-cli/issues/… – Radicel

Answer 5

Please follow these five steps. It's definitely worked (my personal experience)

Step 1: npm uninstall -g @angular/cli

Step 2: npm cache clean --force

Step 3: npm install -g @angular/cli@latest

Step 4: npm i

Step 5: ng build

After that, ng serve.

Cistercian

open in browser type cmd: ng servre --o – Cistercian

Answer 6

If the following command does not work,

npm install --save-dev @angular-devkit/build-angular

then move to the project folder and run this command:

npm install --save @angular-devkit/build-angular

Disappointment

npm install --save @angular-devkit/build-angular worked for me but only problem was I was trying to run this command from a command prompt which was not run as an administrator, and I entered to execute this command it was not showing any error nothing only cursor was on wait state then I simply run a cmd with admin in it worked. Thanks – Presa

Answer 7

I fixed mine by:

1. Delete node_modules folder.

2. run npm install

Yachtsman

Answer 8

All of the previous answers are correct, but they did not work for me. The only way I was able to make this work was by the following steps/commands:

npm uninstall -g @angular/[email protected]
npm cache clean --force
npm install -g @angular/cli@latest
npm install node-sass -g
ng new MY_PROJECT_NAME
cp -r from_my_old_project to_new_MY_PROJECT_NAME

Thine

If you are trying to build a library, use ng new MY_PROJECT_NAME --create-application=false for the second-to-last command. I had this error on trying to build a library. The --create-application=false flag avoids pulling in unnecessary dependencies. (angular.io/guide/creating-libraries#getting-started) – Kawasaki

worked for me after clearing the npm cache and installing again – Stewardson

Answer 9

For Angular 8

Install npm-check-updates package

Run:

$ npm i npm-check-updates
$ ncu -u
$ npm install

This package will update all packages and resolve this issue

Notice: After update If you face this issue:

ERROR in The Angular Compiler requires TypeScript >=3.4.0 and <3.6.0 but 3.6.3 was found instead.

then run:

$ npm install [email protected]

Source Link

Mikimikihisa

'ncu' is not recognized as an internal or external command, operable program or batch file. – Grabowski

Answer 10

npm install

Just type npm install and run. Then the project will run without errors.

Or you can use npm install --save-dev @angular-devkit/build-angular.

Vermicelli

Answer 11

Try this one.

npm install

npm update

If it shows something like this,

Run npm audit fix to fix them, or npm audit for details

Do that!

Gadolinite

And when you do that, NPM says 'I sure hope you know what you are doing.'. That gave me the freaks. – Azarcon

upvoted since it helped - although only partially. After doing this I still had some missing peer dependencies which I install following this idea: https://mcmap.net/q/54737/-how-to-install-npm-peer-dependencies-automatically – Bump

Are you quoting something? If so, what is the source? – Butyrin

Answer 12

The following worked for me. Nothing else did, unfortunately.

npm uninstall @angular-devkit/build-angular
npm install @angular-devkit/build-angular
ng update --all --allow-dirty --force

Keef

I had a message saying --allow-dirty not installed. But updated my stuff. – Southland

Why does it work? An explanation would be in order. E.g., what is the idea/gist? From the Help Center: "...always explain why the solution you're presenting is appropriate and how it works". Please respond by editing (changing) your answer, not here in comments (*** *** *** *** *** without *** *** *** *** *** "Edit:", "Update:", or similar - the answer should appear as if it was written today). – Butyrin

Answer 13

The following commands works:

npm install
ng update

You may see the message "We analyzed your package.json and everything seems to be in order. Good work!"

npm update

Then try a development build:

ng build

I got the error with TypeScript and downgraded to:

npm install typescript@">=3.1.1 <3.2

ng build --prod

All success with a production build.

Below is the working combination:

ng --version

Package                           Version
-----------------------------------------------------------
@angular-devkit/architect         0.11.0
@angular-devkit/build-angular     0.11.0
@angular-devkit/build-optimizer   0.11.0
@angular-devkit/build-webpack     0.11.0
@angular-devkit/core              7.1.0
@angular-devkit/schematics        7.1.0
@angular/cli                      7.1.0
@ngtools/webpack                  7.1.0
@schematics/angular               7.1.0
@schematics/update                0.11.0
rxjs                              6.3.3
typescript                        3.1.6
webpack                           4.23.1

Symptomatic

Answer 14

A working solution for me:

1. Delete the node_modules folder.

2. Run npm install

Coastward

Answer 15

npm install --save-dev @angular-devkit/build-angular@latest

solved it for me.

Devaluate

Answer 16

First delete node_modules folder

then Restart system

Run npm install --save-dev @angular-devkit/build-angular

and

Run npm install

Yoheaveho

Answer 17

When we run commands like ng serve, it uses the local version of @angular/cli. So first install the latest version of @angular/cli locally (without the -g flag). Then update the cli using the ng update @angular/cli command. I thing this should fix the issue.

Angular Update Guide may help you if you are updating your Angular project.

Jurkoic

Answer 18

This error generally occurred when the Angular project was not configured completely.

This will work

npm install --save-dev @angular-devkit/build-angular

npm install

Angelineangelique

Answer 19

Resolve this Error: An unhandled exception occurred: Could not find the implementation for builder @angular-devkit/build-angular:browser###

Just execute the following command and error was solved

• ng update @angular/cli @angular/core

• npm uninstall @angular-devkit/build-angular

• npm install --save-dev @angular-devkit/build-angular ###if this error could not resolve by above command so you update node version###

• npm update npm -g

Whim

Answer 20

Use:

npm i --save-dev @angular-devkit/build-angular

This code installs @angular-devkit/build-angular as a development dependency.

It was 100% tested.

Chamfer

Answer 21

Just update the Angular version and add the below dependency:

ng update

npm update

npm i @angular-devkit/build-angular

https://www.npmjs.com/package/@angular-devkit/build-angular

Sexagesimal

Answer 22

I had a library which I created in an older version of Angular.

Now that I upgraded to the latest version 11 the build would fail.

Indeed, the builder has changed.

When doing an ng build I was something a somewhat similar error message:

Cannot find module '@angular-devkit/build-ng-packagr/package.json'

In the angular.json file I had to change the builder property:

"builder": "@angular-devkit/build-ng-packagr:build",

with:

"builder": "@angular-devkit/build-angular:ng-packagr",

Vertex

Answer 23

1. Go to the folder where you created the angular project and the delete the node_modules folder.

2. Now open the command prompt and enter in the project which you want to run using cd.

3. Enter the command

npm i

or

npm install

4. Now the command prompt will start installing the new node_modules files in the project.

5. When the node_modules gets installed then, run the project using command

   ng s --o

If the above method did not work, then there is some mismatch of the version in npm and then try to install the node_modules.

npm update

Generally, this method should work if not worked then try to run this command:

npm install --save-dev @angular-devkit/build-angular

Details and alternative solution: Could not find module “@angular-devkit/build-angular”.

Estivation

Answer 24

I struggled with the same problem just a minute ago. My project was generated using the version 1.6.0 of angular-cli.

1. npm update -g @angular/cli

2. editing my package.json, changing the line

   "@angular/cli": "1.6.0",
   

   to

   "@angular/cli": "^1.6.0",
   

3. npm update

Palaeography

This has nothing to do with not being able to find a module. this just means the angular cli module will be updated for any version 1.6.x – Symbolist

Answer 25

Try this first

npm install --save-dev @angular-devkit/build-angular

If some error come again for missing packages try

npm install

Graiae

What is it supposed to do? How does it work? What is the idea/gist? From the Help Center: "...always explain why the solution you're presenting is appropriate and how it works". Please respond by editing (changing) your answer, not here in comments (*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** without *** *** *** *** *** *** "Edit:", "Update:", or similar - the answer should appear as if it was written today). – Butyrin

Answer 26

That's works for me, commit and then:

ng update @angular/cli @angular/core
npm install --save-dev @angular/cli@latest

Merchantman

Answer 27

I had the same problem today, after upgrading Node.js from v9 to v10.
My environment is set by Docker and I had to remove this command from the my DockerFile:

npm link @angular/cli

It creates a symbolic link to the directory where Node.js is installed.
I guess the angular/cli module in it do not have the same version as the one in the node_modules directory of my project, and this causes the issue.

Idio

Answer 28

All these answers basically say the same

npm install -D @angular-devkit/build-angular
npm install

But this still may fail if you are in a library project like my-lib which is inside an Angular workspace:

workspace
|-- projects
|    |-- my-lib
|        |-- package.json
|
|-- package.json

In this case, make sure to run npm install not only in the directory workspace/projects/my-lib, but also in workspace directly.

Neckcloth

Answer 29

• Delete the folder node_modules.
• Clear the cache using npm cache clean --verify.
• And then npm install again.

It works like a charm for me.

Azole

Answer 30

I faced the same problem.

Surprisingly, it was just because the version specified in package.json was not in the expected format.

I switched from version "version": "0.1" to "version": "0.0.1" and it solved the problem.

Angular needs semantic versioning (also read Semver) with three parts.

Skyeskyhigh

Answer 31

I had the problem with the newest version of @angular-devkit/build-angular (as of writing this, 11.0.5 was only released 17 hours ago).

Our company is using a Nexus Repository Manager as a npm registry (we do not access https://registry.npmjs.org/ directly). The version was so new, that it wasn't included yet in our Nexus yet.

Invalidating the cache of the repository and npm install fixed the issue.

Display

Answer 32

I had been facing the same issue for two days.

ng -v :6.0.8
node -v :8.11.2
npm -v :6.1.0

Make sure you are in the folder where angular.json is installed. Get into that and type ng serve. If the issue still arises, then you are having only dependencies installed in folder node_modules. Type the following, and it will work:

npm i --only=dev

Luxury

I used ng --version inside the project. It showed me the list with error. So, it means the list didnt had this package installed properly. When I went outside of the app and checked ng --version, so global one didnt even listed it. So, I guess my yarn installtion didnt install the dev dependencies properly – Ptarmigan

Answer 33

Unfortunately, none of the provided solutions worked perfectly for me, but grepit's answer inspired me to do the following steps. I uninstalled Node.js via my OS (Windows 10) and installed it again. Then installed Angular CLI. Then created a new project, and copied my old project's source file into this new one and the error's gone.

Here are the instructions:

1. Uninstall Node.js via your OS and install it again
2. npm install -g @angular/cli
3. Rename your project to YOUR_PROJECT_NAME.old
4. ng new YOUR_PROJECT_NAME
5. Run this Hello, World! project (ng serve) to make sure that you won't get the error.
6. xcopy YOUR_PROJECT_NAME.old\src\*.* YOUR_PROJECT_NAME\src /s

This is the Windows version of copy. Change it based on your own OS.

Slapup

Answer 34

From the Ionic forum, this worked for me.

npm i @ionic/angular-toolkit@latest

Ultrafilter

this is not an ionic project. – Definite

Answer 35

Running the following worked for me:

npm audit fix --force

Cooker

Answer 36

Delete package-lock.json and do npm install again. It should fix the issue.

** This fix is more suitable when you have created Angular 6 app using ng new and after installing other dependencies you find this error.

Dunnite

Answer 37

In my case, the issue was because of missing dependencies. The dependencies were missing, because I had forgotten to call:

npm install

After calling the above command, all required dependencies are loaded in folder node_modules folder, and that isn't an issue any more.

Honorarium

Answer 38

Try this. It worked for me

npm uninstall -g @angular/cli
npm cache verify
npm install -g @angular/cli@next

Varityper

Answer 39

I tried all the previous answers, but none of them worked for me. I had to downgrade the version of Angular-CLI. I run the command ng --version and results:

@angular-devkit/architect          0.10.7
@angular-devkit/build-angular      0.10.7
@angular-devkit/build-ng-packagr   0.10.7
@angular-devkit/build-optimizer    0.10.7
@angular-devkit/build-webpack      0.10.7
@angular-devkit/core               7.0.7 <-- notice this!
@angular-devkit/schematics         8.2.1
@angular/cli                       8.2.1 <-- and this!
@ngtools/json-schema               1.1.0
@ngtools/webpack                   7.0.7
@schematics/angular                8.2.1
@schematics/update                 0.802.1
ng-packagr                         4.7.1
rxjs                               6.3.3
typescript                         3.1.6
webpack                            4.19.1

I open my package.json and search for the line that define the version of CLI:

...
"devDependencies": {
    "@angular-devkit/build-angular": "~0.10.0",
    "@angular-devkit/build-ng-packagr": "~0.10.0",
    "@angular/cli": "~8.2.0" -- I changed here to ~7.0.7
...}
...

I change the version of @angular/cli to ~7.0.7. Then run npm uninstall @angular/cli and install again running npm install -g angular-cli@~7.0.7

Materse

Answer 40

I resolved this by installing Angular on a 64-bit operating system. I was getting the error because I was initially running it on a 32-bit OS.

Argali

What operating system? Linux? Windows? – Butyrin

Answer 41

With the help of the below commands, your application will work as you expected. Run each command as I mention.

1. npm list -g --depth=0
2. npm i npm-check-updates
3. npm install

And finally, run the below command to open your project in the browser:

ng serve --open

Plan

Answer 42

I didn't have a package.json. Make sure you have one.

Tate

Answer 43

For me, it worked when I ran the npm install command inside the project folder.

Example: I have shoppingmenu app and I ran the npm install command inside that folder.

Rhine

Answer 44

This error mostly arises when you don't have Node.js modules in your Angular application.

Developers mostly share Angular applications without the Node.js node_modules folder, because it is very big in size and sharing of applications or uploading takes so much time.

It can be fixed with single command , npm install.

Hartsock

Answer 45

This was the solution for my case: https://github.com/angular/angular-cli/issues/22603

If there is nothing in the folder node_modules\@angular-devkit you might have the same issue.

The devDependencies are not installed because you have set the Environment variable NODE_ENV to production try development instead.

Restart commandline and run npm install and maybe npm i --only=dev

Catchpole

Answer 46

After try many ways, it's still not work until i removed my yarn.lock file

Shantelleshantha

Answer 47

npm i OR npm install

then after, re-run the appliaction.

Engeddi

Answer 48

I just did the below, and it worked.

npm install --save-dev

Eel

unhelpful comment, try answering why it worked, what was failing, etc. – Stereoscope

Answer 49

Your npm version is old. Try to run the following command:

npm i npm@latest -g

Jacklighter

old npm or Node versions does not throw this error "Could not find module “@angular-devkit/build-angular”, the aswear is just install the dependency:npm install --save-dev @angular-devkit/build-angular – Bondstone