When I try to npm run build it shows me this error
$ npm run build
> express@3.2.2 build
> cross-env GENERATE_SOURCEMAP=false react-scripts build
Creating an optimized production build...
Failed to compile.
Cannot read property 'includes' of undefined
how can I know what is causing it? this is my build script
"build": "cross-env GENERATE_SOURCEMAP=false react-scripts build",