突然我的反应是应用程序抛出这个错误
./node_modules/@babel/runtime/helpers/esm/assertThisInitialized.js
Attempted import error: 'default' is not exported from '../assertThisInitialized/_index.mjs'.
早些时候它是工作的，但今天它抛出错误
package.json
"react": "^16.8.6",
"babel-core": "^6.26.3",
"babel-eslint": "^10.0.2",
"babel-jest": "^24.8.0",
"babel-loader": "^7",
"babel-plugin-transform-runtime": "^6.23.0",
"babel-preset-es2015": "^6.24.1",
"babel-preset-react": "^6.24.1",
"babel-preset-stage-0": "^6.24.1",
"babel-runtime": "^6.26.0",
"webpack": "^4.35.3",
尝试指定Babel和webpack的显式版本
使用旧版本的Babel Runtime 7.12.13或更早版本
变通。双击错误文件路径，打开. ./node_modules/@babel/runtime/helpers/esm/assertThisInitialized.js文件，删除'/index. js '。
export {default} from '../assertThisInitialized'
我找到解决办法了。添加"@babel/runtime@7.5.0"在决议包下。Json强制babel-preset-react-app使用@babel/runtime@7.5.0
"resolutions": {
"**/@babel/runtime": "7.5.0"
},