Update V1 to V2 - Error: Cannot find module 'node-sass'

[MaralS]

Description

When I try to to "yarn develop", I'm getting this error.

 error  in ./src/components/molecules/navigation/navigation.scss

Module build failed (from ./node_modules/sass-loader/lib/loader.js):
Error: Cannot find module 'node-sass'
    at Function.Module._resolveFilename (module.js:547:15)
    at Function.Module._load (module.js:474:25)
    at Module.require (module.js:596:17)
    at require (D:\Maral Sabbagh\Documents\Sites\maralsabbagh\node_modules\v8-compile-cache\v8-compile-cache.js:159:
20)
    at Object.sassLoader (D:\Maral Sabbagh\Documents\Sites\maralsabbagh\node_modules\sass-loader\lib\loader.js:46:72
)

 @ ./src/components/molecules/navigation/navigation.scss 2:14-506 21:1-42:3 22:19-511
 @ ./src/components/molecules/navigation/navigation.js
 @ ./src/components/molecules/navigation/index.js
 @ ./src/components/molecules/index.js
 @ ./src/pages/contact.js
 @ ./.cache/sync-requires.js
 @ ./.cache/app.js
 @ multi (webpack)-hot-middleware/client.js?path=/__webpack_hmr&reload=true&overlay=false D://Maral Sabbagh//Documents//Sites//maralsabbagh//.cache//app``` 

I tried to upgrade every gatsby dependencies, I followed the guideline. I don't know why I have this error.
Every help will be appreciated.

[pieh]

Did you install node-sass - it was moved to peer dependency - https://www.gatsbyjs.org/packages/gatsby-plugin-sass/#v200

[MaralS]

@pieh I installed it without the --save-dev flag, that's why I had numerous issues. I installed as a dev dependency and it works now thanks :)