How to Fix: Sass is not working

Sass fails during startup here because the project is trying to compile .scss files without a working Sass toolchain in the local environment. In Vite-based apps, this usually happens when the sass package is missing, incorrectly resolved, or the stylesheet import path does not match the actual file structure.

Understanding the Root Cause

In this repository, the development server starts with Vite, which does not compile Sass/SCSS by itself unless the sass package is available in node_modules. When you run npm run dev, Vite scans imported styles such as .scss files and delegates compilation to Dart Sass.

If sass is not installed, corrupted, or installed under an incompatible dependency tree, the app throws an error before rendering. A second common cause is importing a file like ./styles/main.scss when the actual file name, casing, or location is different. On case-sensitive systems, Styles.scss and styles.scss are not the same file.

Technically, the failure is usually one of these:

• Missing compiler: the project uses SCSS but the sass npm package is absent.
• Broken install: node_modules or the lockfile is out of sync.
• Bad import path: the SCSS import points to a non-existent file.
• Legacy Sass syntax or unsupported setup: older config or deprecated package assumptions cause the build to fail.

Step-by-Step Solution

Follow these steps in order. This resolves the majority of Sass startup errors in Vite projects.

1. Install the Sass compiler explicitly

From the project root, install sass as a development dependency:

npm install -D sass

If the project already has it but still fails, continue with a clean reinstall.

2. Remove the existing dependency tree and lockfile

This clears corrupted package resolution and ensures Vite can detect Sass correctly:

rm -rf node_modules package-lock.json

Then reinstall everything:

npm install

3. Start the dev server again

npm run dev

4. Verify SCSS imports

Check the files imported in your entry files such as main.jsx, main.js, App.jsx, or component-level style imports. Make sure the path and filename casing are correct.

import './styles/main.scss'

If the real file is somewhere else, fix the import path accordingly.

5. Confirm the stylesheet actually exists

For example, if your import is:

import './App.scss'

then the repository must contain that file in the same directory as the importing module.

6. Check package.json for the correct dependency

Your package.json should include sass, not node-sass:

{
  "devDependencies": {
    "sass": "^1.77.0"
  }
}

node-sass is obsolete for modern setups and often breaks on newer Node.js versions.

7. Use a supported Node.js version

If the environment is running an unusual or outdated Node version, dependency compilation may fail. Check your version:

node -v

If needed, switch to a stable LTS release such as Node 18 or Node 20, then reinstall dependencies.

Recommended final fix sequence

npm install -D sass
rm -rf node_modules package-lock.json
npm install
npm run dev

If you want the issue fixed permanently in the repository, make sure sass is committed in package.json so every developer and deployment environment gets the compiler automatically.

Common Edge Cases

• Import casing mismatch: works on one machine but fails on Linux or CI because filename capitalization differs.
• Aliased paths not configured: imports like @/styles/app.scss fail if the Vite alias is missing or incorrect.
• SCSS syntax error: a missing semicolon, bad nesting rule, or invalid variable can look like a Sass setup issue.
• Using node-sass: older tutorials may suggest node-sass, but modern Vite projects should use sass.
• Monorepo or workspace resolution issues: the package may be installed in the wrong workspace, so Vite cannot resolve it from the app directory.
• Cached package manager state: if reinstalling does not help, clear the npm cache and reinstall.

npm cache clean --force
rm -rf node_modules package-lock.json
npm install
npm run dev

FAQ

Do I need both sass and node-sass?

No. Use only sass. It is the supported compiler for modern frontend tooling like Vite.

Why does the project work for someone else but not on my machine?

The most common reasons are a different Node.js version, a corrupted node_modules folder, or a case-sensitive filesystem exposing a bad import path.

Can Vite compile SCSS without extra config?

Yes. Vite supports SCSS automatically as long as the sass package is installed and your file imports are correct.

If you are updating the GitHub issue, the most accurate resolution is: install sass, remove and reinstall dependencies, then verify every imported .scss file path in the project. That addresses the real cause in most Vite Sass failures and is the fastest path to getting npm run dev working again.