Undefined variable: errors in Laravel

When I want to register a user in my laravel project, the page always says

Undefined variable: errors (View: /var/www/resources/views/auth/register.blade.php)"

According to the Laravel documentation, $errors should always automatically be set:

So, it is important to note that an $errors variable will always be available in all of your views on every request, allowing you to conveniently assume the $errors variable is always defined and can be safely used.

I have this on on every view when I use:

@if (count($errors) > 0)
    <div class="alert alert-danger">
        <ul>
            @foreach ($errors->all() as $error)
                <li>{{ $error }}</li>
            @endforeach
        </ul>
    </div>
@endif

or any other way when I want to use the $errors variable.

Why is this? I never had this problem before.

Can someone help please?

via Chebli Mohamed