error An unexpected error occurred: “C:\\Users\\…\\node_modules\\core-js: UNKNOWN: unknown error, open ‘C:\\Users\\…\\AppData\\Local\\Temp\\yarn — 1618462180644–0.671544141967781\\yarn.cmd’”.
go to the directory (AppData/Local/Temp) and delete all directories start with ‘yarn-’
npm uninstall -g create-react-app
npm install npm
npm cache clean --force
npx create-react-app my-app --template typescript