Failed to load PostCSS config V7 and tailwind v4

[emekaokoli]

I'm using React Router as a...

library

Reproduction

after npx create-react-router@latest my-react-router-app and then I run npm run dev it throws this error

appName> npm run dev    

> dev
> react-router dev

node:internal/process/promises:391
    triggerUncaughtException(err, true /* fromPromise */);
    ^

[Failed to load PostCSS config: Failed to load PostCSS config (searchPath: C:/Users/.........../injsubstation): [Error] Loading PostCSS Plugin failed: Cannot find module 'tailwindcss'
Require stack:
- C:\Users\username\postcss.config.js

(@C:\Users\username\postcss.config.js)
Error: Loading PostCSS Plugin failed: Cannot find module 'tailwindcss'
Require stack:
- C:\Users\username\postcss.config.js

System Info

windows: 11
vscode

Used Package Manager

pnpm

Expected Behavior

after the initial installation of the default package and libraries I expect the app to run without throwing error

Actual Behavior

throws postCSS error

Error: Loading PostCSS Plugin failed: Cannot find module 'tailwindcss'

[timdorr]

It appears you have a postcss.config.js file in the directory above your application that is being used. If you remove that, it should work.