The error is You may need an additional loader to handle...。May be your babel-loader can't handle the symbol ??; @babel/plugin-transform-nullish-coalescing-operator can transforms the nullish coalescing operator(??), although this plugin is included in @babel/preset-env, in ES2020, you can try add this plugin to your craco config; If this project runs perfectly fine on the production server and other developers’ machines, check the Node.js version used by other developers and ensure that yours matches, removenode_modules and reinstall again.