Laravel say that Auth guard [] is not defined
This could be a problem in your config/auth.php file, where the 'defaults' array is setting a non-existing guard on Laravel 5.2.
In case you edited your config/auth.php
, e.g. to add another guard and your config is cached, your guards may not be reloaded. If you experience this problem, clearing the config will fix it.
$php artisan config:clear
or $php artisan config:cache
I'm using laravel 5.5
Make sure that your config/auth.php is updated if you've upgraded from 5.1.x to 5.2.
https://github.com/laravel/laravel/blob/v5.2.0/config/auth.php