Versions of @angular/compiler-cli and typescript could not be determined

Question

I have installed Angular/cli and then try to run command ng serve then below error is throwing. I have tried lot of thing like uninstall angular/cli, npm cache clean, etc

Versions of @angular/compiler-cli and typescript could not be determined. The most common reason for this is a broken npm install.

Please make sure your package.json contains both @angular/compiler-cli and typescript in devDependencies, then delete node_modules and package-lock.json (if you have one) and run npm install again.

Answer 1

This may be a problem in not implicitly running devDependencies.

Try running them implicitly with the command below.

npm install --dev

Answer 2

Generic way out to escape this issue

1. Create a new project

   ng new angular-seed

2. Copy all the default dependencies and dev-dependenices from package.json to your current project in use (angular, typescript, etc...)

3. Then remove node_modules and run install npm packages of your current project, or whatever method you use to reubild

   rm -fr node_modules npm install

note: if this doesn't get you the latest version, then you may have global tools installed in roaming data (in window explored browser type %appdata%, and navigate to npm to observe)

Answer 3

1. Open the command prompt in your project folder.

2. Run the command.

 npm install --only=dev