Cannot find module 'ajv/dist/compile/codegen'

[lsaffre]

Describe the bug

I am quite new to the world of npm. When I say "npx create-react-app my-app; cd my-app; npm start" as instructed on the Getting Started page, I get an error message "Cannot find module 'ajv/dist/compile/codegen'"

Did you try recovering your dependencies?

I had to manually say npm install --save-dev ajv to get it to work.

I report this as an issue because it's obviously not intended behaviour, and it's not a nice welcome to beginners. If this happens only on my machine, then I'd like to understand what's wrong with my environment.

Environment

I am using npm version 10.8.2
I did "npm install -g npm@latest" as recommended, removed the my-app directory and tried again, but the issue remains.

(dev) luc@yoga:~/work/my-app$ npm ls -g
/usr/local/lib
├── corepack@0.28.1
├── html-webpack-plugin@5.6.0
├── n@9.2.3
├── npm@10.8.2
├── react-dom@18.3.1
└── typedoc@0.25.3

Environment Info:

current version of create-react-app: 5.0.1
running from /home/luc/.npm/_npx/c67e74de0542c87c/node_modules/create-react-app

System:
OS: Linux 6.5 Ubuntu 22.04.4 LTS 22.04.4 LTS (Jammy Jellyfish)
CPU: (8) x64 11th Gen Intel(R) Core(TM) i7-1185G7 @ 3.00GHz
Binaries:
Node: 20.15.1 - /usr/local/bin/node
Yarn: 1.22.22 - /usr/local/bin/yarn
npm: 10.8.2 - /usr/local/bin/npm
Browsers:
Chrome: Not Found
npmPackages:
react: ^18.3.1 => 18.3.1
react-dom: ^18.3.1 => 18.3.1
react-scripts: 5.0.1 => 5.0.1
npmGlobalPackages:
create-react-app: Not Found

Steps to reproduce

As instructed on https://create-react-app.dev/docs/getting-started :

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

Expected behavior

No error message and the browser starting at http://localhost:3000

Actual behavior

(dev) luc@yoga:~/work/my-app$ npm start

> my-app@0.1.0 start
> react-scripts start

Cannot find module 'ajv/dist/compile/codegen'
Require stack:
- /home/luc/work/my-app/node_modules/ajv-keywords/dist/definitions/typeof.js
- /home/luc/work/my-app/node_modules/ajv-keywords/dist/keywords/typeof.js
- /home/luc/work/my-app/node_modules/ajv-keywords/dist/keywords/index.js
- /home/luc/work/my-app/node_modules/ajv-keywords/dist/index.js
- /home/luc/work/my-app/node_modules/schema-utils/dist/validate.js
- /home/luc/work/my-app/node_modules/schema-utils/dist/index.js
- /home/luc/work/my-app/node_modules/webpack-dev-server/lib/Server.js
- /home/luc/work/my-app/node_modules/react-scripts/scripts/start.js
(dev) luc@yoga:~/work/my-app$ 

[zinebelouarradi]

Run npm uninstall -g create-react-app to remove the global create-react-app package.
Then, try using npx create-react-app my-app again.

npx will automatically download the latest version of create-react-app and use it to set up your project.

[lsaffre]

Run npm uninstall -g create-react-app to remove the global create-react-app package. Then, try using npx create-react-app my-app again.

npx will automatically download the latest version of create-react-app and use it to set up your project.

Thanks for your suggestion. Unfortunately it didn't help.
Your suggestion gave me the idea to try "sudo apt remove npm" followed by "sudo apt install npm". But this too didn't help.

[MosheHM]

this problem happens to me also and i just migrate my app to the now version

[dana-c0914]

Run npm uninstall -g create-react-app to remove the global create-react-app package. Then, try using npx create-react-app my-app again.

npx will automatically download the latest version of create-react-app and use it to set up your project.

I have the same issue when trying to built a new app. I tried uninstalling the global create-react-app as well but with the same result.

Versions:

"react": "^19.0.0",
"react-dom": "^19.0.0",
"react-scripts": "5.0.1",
"web-vitals": "^2.1.4"
node -v -> v18.20.1
npm -v -> 10.5.1

Update

Manually installing the package (as mentioned here ajv-validator/ajv#2443 (comment)) did the trick for me:

npm install ajv --save-dev

[sanyam-saurabh]

Hii , I am facing the same issue , I have tried several methods but it seems npm install ajv --save-dev is the only way for now

[patotoma]

same

[jeppewl]

I have also acquired this issue - a few days ago for no appearant reason. npm install --save-dev ajv@^7 or similar fixes it for the project in question, it seems. There are lots of youtube videos with this solution, but I also need a permanent one. Reinstalling Node.js (upgrade from 20 to 22) didn't help. So I can't figure out if it is factors related to my machine.

[MaNaNchotaliya]

I also had the same problem. I solved it by running: npm install -g npm@latest (in the Node.js Command Prompt) and then trying npm start again

[anr2me]

npm install -g npm@latest (which is currently v11.1.0 on Windows) did solved the npm start issue on a freshly created react-app using npx create-react-app.

But i'm still getting these error/failure during npx create-react-app:

Installing template dependencies using npm...
npm error code ERESOLVE
npm error ERESOLVE unable to resolve dependency tree
npm error
npm error While resolving: client-react@0.1.0
npm error Found: react@19.0.0
npm error node_modules/react
npm error   react@"^19.0.0" from the root project
npm error
npm error Could not resolve dependency:
npm error peer react@"^18.0.0" from @testing-library/react@13.4.0
npm error node_modules/@testing-library/react
npm error   @testing-library/react@"^13.0.0" from the root project
npm error
npm error Fix the upstream dependency conflict, or retry
npm error this command with --force or --legacy-peer-deps
npm error to accept an incorrect (and potentially broken) dependency resolution.
npm error
npm error
npm error For a full report see:
npm error C:\Users\AdamN\AppData\Local\npm-cache\_logs\2025-01-30T00_58_47_692Z-eresolve-report.txt
npm error A complete log of this run can be found in: C:\Users\AdamN\AppData\Local\npm-cache\_logs\2025-01-30T00_58_47_692Z-debug-0.log
`npm install --no-audit --save @testing-library/jest-dom@^5.14.1 @testing-library/react@^13.0.0 @testing-library/user-event@^13.2.1 web-vitals@^2.1.0` failed

Where --force nor --legacy-peer-deps will still shows the same error/failure, but npm config set legacy-peer-deps true made it successful (which previously can't be started due to ajv-related issue).
I wondered why npm config set legacy-peer-deps true shows a different result than --legacy-peer-deps.

Anyway, without npm config set legacy-peer-deps true, if i ignored the failure during npx create-react-app and tried to npm start it, it's no longer getting ajv issue, but i'm seeing this error now:

Failed to compile.

Module not found: Error: Can't resolve 'web-vitals' in 'C:\Data\Projects\NodeTest\client-react\src'
ERROR in ./src/reportWebVitals.js 5:4-24
Module not found: Error: Can't resolve 'web-vitals' in 'C:\Data\Projects\NodeTest\client-react\src'

webpack compiled with 1 error

[alwaysabhishek]

Run npm uninstall -g create-react-app to remove the global create-react-app package. Then, try using npx create-react-app my-app again.
npx will automatically download the latest version of create-react-app and use it to set up your project.

I have the same issue when trying to built a new app. I tried uninstalling the global create-react-app as well but with the same result.

Versions:

"react": "^19.0.0", "react-dom": "^19.0.0", "react-scripts": "5.0.1", "web-vitals": "^2.1.4" node -v -> v18.20.1 npm -v -> 10.5.1

Update

Manually installing the package (as mentioned here ajv-validator/ajv#2443 (comment)) did the trick for me:

npm install ajv --save-dev

yes it works . thanks you i was stuck in it .
but i want to that is it not the permanent solution for this issue or it is the the permanent solution.

[SumedhDV]

npm install ajv --save-dev
THIS works for me

[suresh2648]

npm install ajv --save-dev THIS works for me

ho thank you dear it helped me..