Atualizar Create React App
npm install react-scripts@latest
Tarik
npm install react-scripts@latest
//NPM
npm install --save react@latest
//Yarn
yarn upgrade react@latest
//open terminal and run thsi code
cd newreact
//where newreact is the old react app you created
//open package.json in text editor and change the version to latest
//open the same terminal gain and run this
npm install