What it worked for me was manually update package.json to look like this

"jasmine-core": "~3.8.0",
"karma-jasmine-html-reporter": "^1.7.0"

and then I tried

npm install

but didn't work either so I tried

npm install --legacy-peer-deps

and then everything worked again I was able to do npm start as usual

You can update angular cli globally: npm update @angular/cli -g

Does not help update npm nor node.js. Strange error, strange error mesages. Does help to update package.json - change version of something 'jasmine' - "jasmine-core": "~3.8.0". I don't know what is it for, but it make problems.

Just do the following in the package.json

"jasmine-core": "~3.8.0",

"karma-jasmine-html-reporter": "^1.7.0",

then do npm install

If you're still experiencing this after trying some/all of the above options, Just downgrade npm version from 7 to 6: npm install -g npm@6

install node, if you do not have it or update to the newest version: https://nodejs.org/en/download/package-manager/

update your npm: npm install npm@latest -g

optional : npm i update-node

This will update angular to its newest version: npm install -g @angular/cli Create a new angular project: ng new projectName Change directory the projectName: cd projectName Serve the project ng s

If you are still facing this problem then try to make sure your package.json have all versions matching other supporting library versions. The jasmine-core had to be greater than 3.8 with karma-jasmine-html-report 1.7+

here is how my devDependecies looked inside package.json

"devDependencies": {
    "@angular-devkit/build-angular": "~12.0.0",
    "@angular/cli": "~12.0.0",
    "@angular/compiler-cli": "~12.0.0",
    "@types/jasmine": "~3.6.0",
    "@types/node": "^12.11.1",
    "jasmine-core": "~3.8.0",
    "karma": "~6.3.0",
    "karma-chrome-launcher": "~3.1.0",
    "karma-coverage": "~2.0.3",
    "karma-jasmine": "~4.0.0",
    "karma-jasmine-html-reporter": "^1.7.0",
    "typescript": "~4.2.3"
  }

Edit the package.json in your project folder.

"jasmine-core": "~3.7.0" to "jasmine-core": "~3.8.0", "karma-jasmine-html-reporter": "^1.5.0" to "karma-jasmine-html-reporter": "^1.6.0"

After run npm install in your project folder.

I solved this issue by using this command inside my project directory:

1. npm install --save-dev @angular-devkit/build-angular --force
2. npm audit fix --force

then I ran my project using "ng serve"

Mine is a temporary solution for angular-cli v11.2.12 based on @david-Öztürk answer and on this angular-cli github issue discussions and on its merged fix.

By executing the steps listed on @david-Öztürk answer I was still getting the same error. And also the fix is more conservative than the proposed solution. I hope it helps someone else:

Run the Angular project creation without automatic npm packages installation:

ng new --skip-install <project-name>

Enter project directory:

cd <project-name>

Edit package.json and change this...

"karma-jasmine-html-reporter": "^1.5.0",

...to this:

"karma-jasmine-html-reporter": "~1.5.0",

Manually install npm packages:

npm install

Error Details after doing ng new my-app

npm ERR! Could not resolve dependency:

npm ERR! peer jasmine-core@">=3.7.1" from karma-jasmine-html-reporter@1.6.0

Fix Details

1. sudo npm install -g npm@7.13.0 => updated npm from 7.10.0 to 7.13.0
2. Only changed "jasmine-core" from 3.6.0 to 3.7.1 i.e "jasmine-core": "~3.7.1", in package.json
3. npm install

After this found no issues and I was able to do ng build and ng serve.

Other settings I left as it was : "@types/jasmine": "~3.6.0", "jasmine-spec-reporter": "~5.0.0",

They have released Karma Jasmine html reporter few hours ago. This maybe what is breaking the code. The update is most likely the cause.

You should change the package.json and get the older version of the Karma Jasmine older version

Open the folder you create with ng new and open the package.json file. In devDependencies change the version of "jasmine-core" 3.6.0 to 3.8.0 and "karma-jasmine-html-reporter" from 1.7.0 to 1.6.0 and save it. Then go back to Terminal and go to your project and run npm install. Now it works and you can run ng serve.

Edit 2021

"jasmine-core": "~3.8.0",
"karma-jasmine-html-reporter": "^1.7.0"

Looks like the issue with latest NPM 7.12.0 and the latest Node 16.1.0(Current Version)

In my case I followed the below steps -

1. Uninstall Node
2. Re-Install the Latest Node (LTS: 14.16.1)
   • Which will install the latest NPM : 6.14.12
3. Run the ng new my-app

I had the same problem and I solved it with reinstalling nodeJs 14.16.1 but I had to change the version of npm manually with the command

npm install -g npm@6.14.12

After of course, I tested the modifications by creating a project

ng new <MyProjet>