Laravel 5.5 login and register page says:The page has expired due to inactivity.[TokenMismatchException]

i think you missed csrf token.

dont forget to use {!! csrf_field() !!}

In my case, I've got the same error message and then figured that I missed to add csrf_token

{{ csrf_field() }}

Or without form helper that will be,

<input type="hidden" name="_token" value="{{ csrf_token() }}">

If that doesn't work, then-

Refresh the browser cache and hopefully it will work, thanks.

I had the same problem on localhost:8000 (php artisan serve). Maybe it's coincidence, but try on "clean browser" , other than you used with previous development. For me it worked.

It seems that the problem is with cookies from development with previous Laravel versions, on the same url.