事情发生在我安装element-plus之后，vue服务器直接报错了。
然后，查看了一下npm list，最后执行了npm install sass-loader
好了
Syntax Error: Error: PostCSS received undefined instead of CSS string
相关文章
- 10-24微信小程序错误提示：readFile:fail parameter error: parameter.filePath should be String instead of Undefined;
- 10-24Syntax Error: Error: PostCSS received undefined instead of CSS string
- 10-24Syntax Error: Error: PostCSS received undefined instead of CSS string at runMicrotasks
- 10-24Syntax Error: Error: PostCSS received undefined instead of CSS string