Why npm start is throwing events.js:187 throw er; // Unhandled 'error' event in my react project?

Question

While starting the server for the first time just after the code checkout , my react js project is throwing error "events.js:187 throw er; // Unhandled 'error' event" . I have node 12.13.0 and npm 6.12.0 . Log file attached log file

events.js:187
      throw er; // Unhandled 'error' event
      ^



    Error: spawn cmd ENOENT
        at Process.ChildProcess._handle.onexit 
       (internal/child_process.js:264:19)
       at onErrorNT (internal/child_process.js:456:16)
       at processTicksAndRejections (internal/process/task_queues.js:80:21)
    Emitted 'error' event on ChildProcess instance at:
       at Process.ChildProcess._handle.onexit (internal/child_process.js:270:12)
       at onErrorNT (internal/child_process.js:456:16)
       at processTicksAndRejections (internal/process/task_queues.js:80:21) {
    errno: 'ENOENT',
    code: 'ENOENT',
    syscall: 'spawn cmd',
    path: 'cmd',
    spawnargs: [ '/c', 'start', '""', '/b', 'http://localhost:3000/' ]
}

@Priyam can you attach your package.json? Also try to downgrade the version of react and re install it. https://github.com/facebook/create-react-app/issues/7061 this could help you! — Ayushi Keshri, Oct 29 '19 at 12:37
refer from here @AyushiKeshri https://drive.google.com/open?id=1eVj5WgTaQSHOahJE_eN5c6yixYs_Ip_- — Priyam, Oct 29 '19 at 14:57
downgrade the version of react-script from 3.0.1 to 2.1.8 and try npm install @Priyam — Ayushi Keshri, Oct 29 '19 at 17:47
@AyushiKeshri Downgrading the version to 2.1.8 worked for me. Thank you so much for your help :) — Priyam, Nov 22 '19 at 09:49

monster chen · Answer 1 · 2019-11-19T08:23:15.253

4

If your system is windows, set your environment variable, add %SystemRoot%\system32 to your PATH I met this error yesterday，hope it works to you. Don't forget reboot you PC

edited Nov 19 '19 at 08:23

answered Nov 06 '19 at 07:25

monster chen

41
4

score 2 · Accepted Answer · edited Nov 27 '20 at 15:04

2

Downgrading the react-script version from 3.0.1 to 2.1.8 worked for me. Follow the following commands in sequence:- npm install react-scripts@2.1.8 npm install npm start

edited Nov 27 '20 at 15:04

Suprabhat Kumar

645
7
13

answered Nov 22 '19 at 09:51

Priyam

153
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score 2 · Answer 3 · answered Apr 29 '20 at 12:22

Try this if none of the above answers solved u.. Go to My Computer>Properties>Advanced and in the environment variables Edit the PATH and add the following

C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem; C:\Program Files\nodejs;C:\Users{yourName}\AppData\Roaming\npm

Add 4 of them and restart your PC

score 1 · Answer 4 · answered Oct 29 '19 at 09:03

1

You can use node Your_File_Name.js command to run from the localhost. To use npm start command, you need to use scripts array in your package.json file "scripts": { "start": "http://localhost:3000/" } If this is not helpful can you attach more details?

answered Oct 29 '19 at 09:03

Imran Hussain

152
6

can you attach the package.json file as well – Imran Hussain Oct 29 '19 at 12:50
https://drive.google.com/open?id=1eVj5WgTaQSHOahJE_eN5c6yixYs_Ip_- – Priyam Oct 29 '19 at 14:57
1

I don't see the dependency for `react-scripts` in the dependency array. You can use the command `npm install react-scripts --save`. – Imran Hussain Oct 29 '19 at 15:56

score 1 · Answer 5 · edited Nov 02 '19 at 18:07

1

Try to execute export PATH=$PATH:/mnt/c/Windows/System32. Change the path /mnt/c/ to the path mounted on your wsl Windows (mount).

if it works, insert the path /mnt/c/Windows/System32 into the file /etc/environment.

here in my case this solution worked

edited Nov 02 '19 at 18:07

dmigo

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answered Nov 02 '19 at 17:52

Junior Alves

11
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score 1 · Answer 6 · edited Jul 18 '20 at 17:35

I faces this issue while using the windows subsystem for Linux and solved it by adding C:\Windows\System32 to Environment Variables Path. Environment Variables can add as follow.

go to

control panel -> System and Security ->System -> Advanced System Settings.

From the appearing dialog box, select Environment Variables, and then under System Variables select the path and select edit and add C:\Windows\System32. Restart the machine.

score 1 · Answer 7 · answered Feb 26 '21 at 21:41

Just in case this helps someone else, I started using react-scripts@4.0.3 from a version of create-react-app that didn't include it, and suddenly I got this error.

It turned out the hot reload websocket was attempting to make a connection from the browser to my dev server, but it failed and crashed the app.

I found the fix here: I added transportMode: "ws" to my webpackDevServer.config.js beneath hot: true, and it worked.

Creeptosis · Answer 8 · 2019-11-05T01:45:53.620

0

Make sure all the global & local packages that are being used in the scripts are installed, I've spent hours debugging an issue while deploying an application because webpack-cli & yarn wasn't installed globally & my project was trying to access it locally.

edited Nov 05 '19 at 01:45

answered Nov 05 '19 at 01:35

Creeptosis

176
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score 0 · Answer 9 · edited Jan 04 '20 at 10:25

0

In your package.json file try lowering the version of "react-scripts" to "2.1.8":

"dependencies": { 
    "@testing-library/jest-dom": "^4.2.4",  
    "@testing-library/react": "^9.4.0",  
    "@testing-library/user-event": "^7.2.1",  
    "react": "^16.12.0",  
    "react-dom": "^16.12.0",  
    "react-scripts": "2.1.8"  
  },

Above works for me.

edited Jan 04 '20 at 10:25

סטנלי גרונן

2,917
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answered Jan 04 '20 at 09:58

Md Yeasin Arafat

2,683
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score 0 · Answer 10 · answered May 28 '20 at 17:44

0

If you are experiencing this error on ubuntu simply prepend "sudo" to the npm start command. That is sudo npm start

answered May 28 '20 at 17:44

Marvelous Ikechi

2,031
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score 0 · Answer 11 · answered Jun 12 '20 at 17:58

0

downgrading react-scripts to npm install react-scripts@2.1.8 works for me

answered Jun 12 '20 at 17:58

codemon

11

1

It would be helpful to share context on why this solution would work. Also, "X works for me" is probably not the right level of confidence for an answer. – rahul Jun 12 '20 at 19:13

score 0 · Answer 12 · answered Jul 02 '20 at 07:46

0

in my case react-scripts was missing from the devDependencies adding it in devDependencies resolved it for me. Hope this helps

answered Jul 02 '20 at 07:46

Ahmed J.

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score 0 · Answer 13 · answered Jan 22 '21 at 09:25

If downgrading react-scripts not working for you please follow below steps

Search Edit the system environment variable and open it.
Click on Environment Variables.
Select Path in system variables section and click on Edit.
Click on New and add this %SystemRoot%\system32
Click on OK everywhere and restart the system.

score 0 · Answer 14 · answered Mar 30 '21 at 15:11

0

Try adding the following environment variables to PATH. (System variables)

C:\Windows\system32
C:\Windows
C:\Windows\System32\Wbem

They should be there by default but mine were missing for someone reason. I added them and the problem disappeared.

answered Mar 30 '21 at 15:11

Ian Gibblet

552
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score 0 · Answer 15 · answered Jun 20 '21 at 05:23

0

Had the same problem in windows, deleting the node_modules and then a npm install fixed it for me.

answered Jun 20 '21 at 05:23

milindsoorya

63
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score 0 · Answer 16 · answered Jan 11 '23 at 08:39

0

In my case upgrading the Node.js to the latest LTS version (18.13.0) fixed the issue on my Windows 10 machine.

answered Jan 11 '23 at 08:39

Wasid Hossain

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1
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Why npm start is throwing events.js:187 throw er; // Unhandled 'error' event in my react project?

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