The react-scripts package provided by Create React App requires a dependency:

create .env file in your project file and add the following statement

SKIP_PREFLIGHT_CHECK=true

Save the file

Remove node_modules, yarn.lock, package.lock

Then reinstall node_modules with

npm install

This should work

I had the same problem and do all the suggested steps but the problem still, so, my error is that i have a reactApp inside other Javascript App i had this structure.

--MyProjects
----NodeJsApp
----node_modules of NodeJsApp
----package.json of NodeJsApp
----ReactApp
------node_modules of ReactApp
------package.json of ReactApp

The problem solved to me deleting my ReactApp node_modules directory, then i do a reestructure of my directories because i have a disaster.

--MyProjects
----NewDirectory (inside all about NodeJsApp)
------node_modules of NodeJsApp
------package.json of NodeJsApp
----ReactApp
------package.json of ReactApp

After that i do :

npm install

and then npm start and my problem has fixed, i think that the problem is that the parent directory cant have a javascript /nodeJs/ project or something that have node_modules .

Part of the output you provided says:

Check if C:\Users\chawki\node_modules\babel-eslint is outside your project directory. For example, you might have accidentally installed something in your home folder.

Browse to C:\Users\chawki\node_modules\ and delete the babel-eslint folder, or simply delete C:\Users\chawki\node_modules.

I just deleted the node_modules folder (for me it was C:\user\[yourUserName]\node_modules\) and re-installed it.

Here What i did...

1. C:\user\[yourUserName]\node_modules\babel-eslint and delete the file
2. C:\user\[yourUserName]\node_modules\eslint and delete the file

Delete your eslint and babel-eslint file from your node modules on your computer e.g. -C:\Users\vishnu\node_modules -delete eslint and babel-eslint file.

In your project:

yarn remove eslint
yarn add --dev eslint@6.1.0

yarn remove babel-eslint
yarn add --dev babel-eslint@10.0.3

If you dont want to create .env file there is another alternative you can pass the SKIP_PREFLIGHT_CHECK=true directly in the script. For Example

   "start": "SKIP_PREFLIGHT_CHECK=true react-scripts start",

in package.json

resolutions:{
    "babel-eslint": "9.0.0"
}

if you reinstall your all dependencies, you will be forcing "babel-eslint" to be version "9.0.0". if you start your app, you will have no issue.

My problem was I installed webpack as a global package... after i deleted webpact and run npm install, the problem was gone

Make sure you don't have a global webpack package or somewhere higher up the directory structure. In my case, I had it globally installed. Deleting and then running npm install and then npm start worked perfectly.

Run npm ls babel-eslint and see which dependencies are using it or installing another version. Try updating those libraries.

It worked for me.