After introducing element-ui, there is a problem of Module parse failed: Unexpected character'@'.

problem description

VUE project. After introducing element-ui, Module parse failed: Unexpected character"@"

appears.

the environmental background of the problems and what methods you have tried

there should be no corresponding loader in the analysis. I searched a lot of solutions on the Internet and added a lot of loader, but none of them solved

related codes

Code for introducing element-ui into main.js:

"devDependencies": {
    "babel-core": "^6.26.0",
    "babel-loader": "^7.1.2",
    "babel-preset-env": "^1.6.0",
    "babel-preset-stage-3": "^6.24.1",
    "cross-env": "^5.0.5",
    "css-loader": "^0.28.7",
    "file-loader": "^1.1.4",
    "less": "^3.0.4",
    "less-loader": "^4.1.0",
    "style-loader": "^0.23.1",
    "url-loader": "^1.1.2",
    "vue-loader": "^13.0.5",
    "vue-template-compiler": "^2.4.4",
    "webpack": "^3.6.0",
    "webpack-dev-server": "^2.9.1"
  },