Why is npm start (after create-react-app) failing to run?

Question

After I create a sample react app using create-react-app, npm start fails.

I have tried this using node 11.4 and 10.4 (npm 6.4.1)

npm install create-react-app -g
create-react-app t2
cd t2
npm start

Expected

To be able to start simple react server to hit in browser at localhost:3000

Actual

Server did not start, got this in my terminal:

$ npm start

> [email protected] start /Users/samr/dev/githubs/react/t2
> react-scripts start

/Users/samr/dev/githubs/react/t2/node_modules/ajv/lib/keyword.js:65
      throw new Error('custom keyword definition is invalid: '  + this.errorsText(validateDefinition.errors));
      ^

Error: custom keyword definition is invalid: data.errors should be boolean
    at Ajv.addKeyword (/Users/samr/dev/githubs/react/t2/node_modules/ajv/lib/keyword.js:65:13)
    at module.exports (/Users/samr/dev/githubs/react/t2/node_modules/ajv-errors/index.js:10:7)
    at Object.<anonymous> (/Users/samr/dev/githubs/react/t2/node_modules/schema-utils/src/validateOptions.js:22:1)
    at Module._compile (internal/modules/cjs/loader.js:723:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:734:10)
    at Module.load (internal/modules/cjs/loader.js:620:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:560:12)
    at Function.Module._load (internal/modules/cjs/loader.js:552:3)
    at Module.require (internal/modules/cjs/loader.js:659:17)
    at require (internal/modules/cjs/helpers.js:22:18)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! [email protected] start: `react-scripts start`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the [email protected] start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/samr/.npm/_logs/2019-02-09T23_19_40_848Z-debug.log

Looks like a known issue: github.com/webpack/webpack/issues/8768 — Lambda Fairy
– Lambda Fairy, Commented Feb 9, 2019 at 23:47
I'm running into this as well. Npm start worked fine for me for an app I created last night, but today I tried to use create-react-app for a new project, and in the new project npm start is not working for me. Copying over my node_modules folder from my previous app did help as a temporary workaround, but once I tried installing react router into my new app and then running npm start, I'm running into this error once again. — cathamatic
– cathamatic, Commented Feb 10, 2019 at 0:07
same here, maybe you can check this github.com/webpack/webpack/issues/8768, changing the file in file node_modules\ajv-errors\index.js as someone says here solved it for now as a quick fix — PepitoPompin
– PepitoPompin, Commented Feb 10, 2019 at 0:16

aquilesb · Accepted Answer · 2019-02-10 02:03:49Z

11

As @atsnam has said, you can find the resolution here https://github.com/webpack/webpack/issues/8768.

If you use yarn

add below to package.json

"resolutions": {
  "ajv": "6.8.1"
}

then run yarn install

if you use npm

npm uninstall ajv
npm install [email protected]

That worked for me

answered Feb 10, 2019 at 2:03

aquilesb

2,2721 gold badge20 silver badges21 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

jsnewbie Over a year ago

it won't work if you deploy the app. i suggest adding "ajv": "6.8.1" into the dependencies instead

aquilesb Over a year ago

Just modify to npm install --save [email protected]

Lambda Fairy Over a year ago

if you're using npm 5 or newer, all installs should be saved to package.json by default

Dan7el Over a year ago

I had the same issue with a TomTom ReactJS sample I got off GitHub. This answer resolved the problem.

Nicolás Alarcón Rapela · Accepted Answer · 2019-09-14 13:47:46Z

9

Quick fix is mentioned here :

GITHUB - webpack/issues/8768

Essentially go to node_modules/ajv/lib/keyword.js and comment out lines 64 and 65.

edited Sep 14, 2019 at 13:47

Nicolás Alarcón Rapela

3,0621 gold badge21 silver badges35 bronze badges

answered Feb 10, 2019 at 0:16

atsnam

3891 gold badge2 silver badges9 bronze badges

1 Comment

Abel Agoi Over a year ago

There is no ajv folder in my node_modules directory

jsnewbie · Accepted Answer · 2019-02-10 13:23:06Z

1

just add resolutions to your package.json like this:

  { 
    "dependencies": {
      ...
    }
    "resolutions": {
      "ajv": "6.8.1"
    }
  }

then run npm install. if you use yarn, yarn install

edited Feb 10, 2019 at 13:23

jsnewbie

1,83915 silver badges9 bronze badges

answered Feb 10, 2019 at 0:01

nik.ss

811 silver badge8 bronze badges

1 Comment

javazen Over a year ago

I added this, did the npm install, but npm start still fails the same way.

Varad · Accepted Answer · 2019-02-10 00:17:40Z

0

As per the suggestion in Github answers the below change has enabled me to work.

To fix this error, just change:
Line 14: `errors: 'full',`
to:
Line 14: `errors: true`
in file **node_modules\ajv-errors\index.js**

answered Feb 10, 2019 at 0:17

Varad

1,02213 silver badges27 bronze badges

Comments

taurus05 · Accepted Answer · 2020-02-18 06:51:40Z

0

The accepted answer didn't work for me. Instead i did this:

deleted node_modules folder.
cd to project parent directory.

npm install
npm start

This worked like a charm.

answered Feb 18, 2020 at 6:51

taurus05

2,56420 silver badges31 bronze badges

Collectives™ on Stack Overflow

Why is npm start (after create-react-app) failing to run?

Expected

Actual

5 Answers 5

If you use yarn

4 Comments

1 Comment

1 Comment

Comments

Comments

Hot Network Questions

Collectives™ on Stack Overflow

Expected

Actual

5 Answers 5

If you use yarn

4 Comments

1 Comment

1 Comment

Comments

Comments

Related