Vue项目执行npm run serve时出现TypeError: Cannot read properties of undefined (reading 'spaces')错误求助

Hey there, that error you're hitting when running npm run serve is almost always tied to version mismatches between your Sass-related dependencies. Let's walk through how to fix this based on your current setup:

1. Uninstall the Conflicting Packages First #

Start by removing the existing versions of node-sass and sass-loader that are causing the clash:

npm uninstall node-sass sass-loader

2. Install a Compatible Dependency Combo #

You have two reliable options here:

Option 1: Switch to Dart Sass (Recommended) #

Node Sass is officially deprecated, so moving to Dart Sass (the modern, supported alternative) will avoid future compatibility headaches. Install the matching versions:

npm install sass sass-loader@12.6.0 --save-dev

Note that sass is the package name for Dart Sass, and version 12.6.0 of sass-loader plays nicely with it across most Vue CLI versions.

Option 2: Stick with Node Sass (Not Recommended) #

If you need to keep using Node Sass for specific reasons, you'll need to pair node-sass@6.0.0 with a compatible sass-loader version (v11.x works perfectly here):

npm install node-sass@6.0.0 sass-loader@11.1.0 --save-dev

3. Clean Up and Restart Your Service #

To ensure all dependencies sync correctly:

• Delete your node_modules folder and package-lock.json file
• Reinstall dependencies with:

npm install

• Run npm run serve again — the error should be resolved!

If you're using Vue CLI 5+, Option 1 is the best fit since it aligns with the CLI's default recommendations.

内容的提问来源于stack exchange，提问作者EaBengaluru