React npm start doesn't work after create-react-app

All we need is an easy explanation of the problem, so here it is.

I’m learning just React and my english is poor. I have already two react project but they don’t work either ๐Ÿ™ I following this steps,

npx create-react-app my-app
cd my-app
npm start

but it doesn’t work. I try clean cache and npm install again but didn’t succeed. how can i solve this?

> [email protected] start /Users/edu/Documents/htdocs/my-app
> react-scripts start

There might be a problem with the project dependency tree.
It is likely not a bug in Create React App, but something you need to fix locally.

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

  "babel-loader": "8.0.5"

Don't try to install it manually: your package manager does it automatically.
However, a different version of babel-loader was detected higher up in the tree:

  /Users/edu/node_modules/babel-loader (version: 8.1.0) 

Manually installing incompatible versions is known to cause hard-to-debug issues.

If you would prefer to ignore this check, add SKIP_PREFLIGHT_CHECK=true to an .env file in your project.
That will permanently disable this message but you might encounter other issues.

To fix the dependency tree, try following the steps below in the exact order:

  1. Delete package-lock.json (not package.json!) and/or yarn.lock in your project folder.
  2. Delete node_modules in your project folder.
  3. Remove "babel-loader" from dependencies and/or devDependencies in the package.json file in your project folder.
  4. Run npm install or yarn, depending on the package manager you use.

In most cases, this should be enough to fix the problem.
If this has not helped, there are a few other things you can try:

  5. If you used npm, install yarn ( and repeat the above steps with it instead.
     This may help because npm has known issues with package hoisting which may get resolved in future versions.

  6. Check if /Users/edu/node_modules/babel-loader is outside your project directory.
     For example, you might have accidentally installed something in your home folder.

  7. Try running npm ls babel-loader in your project folder.
     This will tell you which other package (apart from the expected react-scripts) installed babel-loader.

If nothing else helps, add SKIP_PREFLIGHT_CHECK=true to an .env file in your project.
That would permanently disable this preflight check in case you want to proceed anyway.

P.S. We know this message is long but please read the steps above :-) We hope you find them helpful!

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/edu/.npm/_logs/2020-09-17T00_43_20_777Z-debug.log

How to solve :

I know you bored from this bug, So we are here to help you! Take a deep breath and look at the explanation of your problem. We have many solutions to this problem, But we recommend you to use the first method because it is tested & true method that will 100% work for you.

Method 1

Take a look at suggestion number 6 in your output.

Check if /Users/edu/node_modules/babel-loader is outside your project directory.
For example, you might have accidentally installed something in your home folder.

It sounds like at some point you accidentally did an npm install in your home folder (/Users/edu/) instead of your project folder, and your project is picking up on this dependency.

The fix is to delete node_modules, package.json, and package-lock.json from /Users/edu/, those don’t need to be there.

For other Googlers: The above fix might not fix your specific issue – take a read through the error message and see if any of the other suggestions help out. Often times error messages are pretty useless, but every once in a while, someone actually takes the time to write out something helpful. This is one of those well-done errors.

Method 2

Maybe try:

npm cache clean

npm install

npm create-react-app my-app

cd my-app

npm run start

Note: Use and implement method 1 because this method fully tested our system.
Thank you ๐Ÿ™‚

All methods was sourced from or, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0

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