Node.js에서 모듈 설치 시에 다음과 같은 "self signed certificate in certificate chain" 에러를 만나게 되었을 때 아래 명령어로 해결 가능하다. $ set NODE_TLS_REJECT_UNAUTHORIZED=0 $ set npm_config_strict_ssl=false npm WARN read-shrinkwrap This version of npm is compatible with lockfileVersion@1, but package-lock.json was generated for lockfileVersion@2. I'll try to do my best with it! > geckodriver@3.0.1 postinstall D:\workspace\tist..