INFO Starting development server.... ERROR Error: Rule can only have one resource source (provided

problem¶

When writing a vue-cli project, the following problems occurred when running npm run serve

After consulting the information, I know that I have installed the latest version of sass-loader. It may be because the version is too new and is not compatible with project plugins or dependencies.

solution¶

Type in the terminal
Delete the newer version first

npm uninstall sass-loader

Install a lower version

npm install sass-loader@8.0.0 --save-dev