unhandledRejection: TypeError: Cannot read properties of null (reading 'useReducer')

[Kamadarada]

Summary

Hey guys!

i started my studies with next.js and i got this error when i'm trying to run the application.

"unhandledRejection: TypeError: Cannot read properties of null (reading 'useReducer')"
but i'm not using "useReducer" in any archive.

already tried to downgrade react

Additional information

No response

Example

No response

[Kamadarada]

Here is how i solved it:

• yarn set version stable
• yarn install
• yarn cache clean
• yarn dev

apparently it was just the yarn cache

[khokonm]

I'm using NPM, still facing the issue on newly created nextjs project, how do I solve?

[Kamadarada]

the problem was yarn cache. So try clearing npm cache

[akhilravidas]

npm install -g npm@latest
npm install
npm cache clean --force
npm run dev

[khokonm]

Turns out, the issue was specific to my device due to how I initially set up Next.js. After almost eight months, I finally fixed the issue and was able to run a Next.js project again. If anyone else is facing the same problem, feel free to check out the detailed documentation I wrote on how I fixed the issue!.

[Vancelott]

@khokonm Your blog post saved me after trying to debug this error for two days, thanks a ton!