0

I cloned my project from github and i can't manage to re-install react and launch react environement. I installed Node.js on my PC, and i ran : npm install react react-dom and npm install

I have this message error when i run npm start :


> [email protected] start C:\Users\vellu\Documents\warhammer-game-react
> 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:

  "webpack": "4.41.2"

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

  C:\Users\vellu\Documents\warhammer-game-react\node_modules\webpack (version: 4.42.0)

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 "webpack" 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 (http://yarnpkg.com/) 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 C:\Users\vellu\Documents\warhammer-game-react\node_modules\webpack is outside your project directory.
     For example, you might have accidentally installed something in your home folder.

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

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! 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!     C:\Users\vellu\AppData\Roaming\npm-cache\_logs\2020-03-08T18_39_19_297Z-debug.log

I tried to delete node_modules and delete package-lock.json, and delete the webapack line as mentioned, then re-run npm install it still show me this error message. I also tried with yarn, and same problem. Anyone has suggestion?

6 Answers 6

3

I also faced a similar problem. Then as per the instruction in the error message I have created a .env file in the project directory and add the below line and i'm able to successfully start the application.

SKIP_PREFLIGHT_CHECK=true
1

Two Possible Solutions:

1. To solve it locally Add a .env file in your root folder, containing this line:

SKIP_PREFLIGHT_CHECK=true

2. For a global solution

npm uninstall -g webpack

npm i -g [email protected]
0

Try cleaning NPM cache then do instructions in error message above again; Since npm install won't download a package that is already found in cache, which is a cool feature but in rare cases a package may corrupt and package manager will fetch that problematic package again and again for npm install; cleaning cache will also cause all packages to be re-downloaded which takes a lot longer than a usual npm install.

0

You could try updating react-scripts which might fix this issue.

Refer https://github.com/facebook/create-react-app/blob/master/CHANGELOG.md and try updating react-scripts version by version.

If you want to know the current version, you can refer package.json file.

0

I had also the same problem. I tried Senthuran's solutions before. But it doesn't resolve the problem permanently. So then I tried :

npm uninstall -g webpack

If it didn't work. Remove webpack folder manually from global node_modules folder in your pc.

-1

Install webpack:

npm install react react-dom npm webpack

If that works, open package.json, and you'll see a line like the webpack one below...

  5   "dependencies": {
....
  9     "react": "^16.12.0",
 10     "react-dom": "^16.7.0",
 11     "react-scripts": "^1.1.4",
 12     "react-tooltip": "^3.9.0",
 13     "webpack": "^3.11.0",

Then npm start should work.

Not the answer you're looking for? Browse other questions tagged or ask your own question.