`popstate` called with empty state
Why This Error Occurred​
When using the browser back button the popstate event is triggered. Next.js sees a
popstate event being triggered but event.state did not have url or as, causing a route change failure.
Possible Ways to Fix It​
The only known cause of this issue is manually manipulating window.history instead of using next/router. Starting from version 9.5, Next.js will ignore popstate events that contain event.state not created by its own router.