An unhandled exception occurred: Could not find module "@angular-devkit/build-angular"

Question

When running the terminal commands ng server or ng serve I'm getting this issue:

An unhandled exception occurred: Could not find module "@angular-devkit/build-angular"

Answer 1

Check in your package.json to see if you have this package in your devDependencies section or not

"devDependencies": {
    "@angular-devkit/build-angular": "~0.803.18"
}

If exist try to

delete package-lock.json or yarn-lock.json

run

npm cache clean --force

then run

npm i

Answer 2

Install @angular-devkit/build-angular as dev dependency.

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

or,

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