No Unwanted Polyfill.io
Prevent duplicate polyfills from Polyfill.io.
Why This Error Occurred​
You are using polyfills from Polyfill.io and including polyfills already shipped with Next.js. This unnecessarily increases page weight which can affect loading performance.
Possible Ways to Fix It​
Remove all duplicate polyfills. If you need to add polyfills but are not sure if Next.js already includes it, take a look at the list of supported browsers and features.