여느때와 마찬가지로 새로운 React 프로젝트를 설치하고, yarn start를 통해 시작하려던 와중에 생전 처음 보는 에러가 발생했다. There might be a problem with the project dependency tree. It is likely not a bug in Create React App, but something you need to fix locally. The react-scripts package provided by Create React App requires a dependency: "webpack": "4.42.0" Don't try to install it manually: your package manager does it automatically...