맥북 os 세콰이어에서 node js 를 설치하고 npm run start 를 실행했더니, 이런 에러 메세지가 나왔었습니다. Failed to compile. Module not found: Error: Can't resolve 'web-vitals' in '/Users/danymac/Desktop/hello_react/src' ERROR in ./src/reportWebVitals.js 5:4-24 Module not found: Error: Can't resolve 'web-vitals' in '/Users/danymac/Desktop/hello_react/src' webpack compiled with 1 error One of your dependencies, babel-preset-react-a..