You seem to not be depending on "@angular/core". This is an error

Try to run

npm install

in the project folder

angular npm angular-cli

While running ng serve you should be in the app's/project's directory.

If you run the command in another directory you get the error:

You seem to not be depending on "@angular/core". This is an error.

angular npm angular-cli

Delete your node modules , Check your package.json file should have the @angular/core and reinstall it with npm i.

CodeHunter