Error with Laravel authentication - authentication

Question

I'm new to Laravel and I am trying to implement authentication in my application, when I post the login form this error is returned in my browser:
I have no idea what this error means, where it occurs, or how to fix it.
This is my signin function in my authentication controller that handles all logins:
public function signin()
{
// validate the info, create rules for the inputs
$rules = array(
'email' => 'required|email', // make sure the email is an actual email
'password' => 'required|min:6' // password can only be alphanumeric and has to be greater than 3 characters
);
// run the validation rules on the inputs from the form
$validator = Validator::make(Input::all(), $rules);
// if the validator fails, redirect back to the form
if ($validator->fails()) {
return Redirect::to('/authentication')
->withErrors($validator) // send back all errors to the login form
->withInput(Input::except('password')); // send back the input (not the password) so that we can repopulate the form
} else {
// create our user data for the authentication
$user = array(
'email' => Input::get('email'),
'password' => Input::get('password')
);
// attempt to do the login
if (Auth::attempt($user)) {
// validation successful!
// redirect them to the secure section or whatever
// return Redirect::to('secure');
// for now we'll just echo success (even though echoing in a controller is bad)
return Redirect::to('dashboard.index');
} else {
// validation not successful, send back to form
return Redirect::to('/authentication')
->with('failed', 'Incorrect email / password!');
}
}
}
This is my User model:
<?php
class User extends Eloquent{
// MASS ASSIGNMENT -------------------------------------------------------
// define which attributes are mass assignable (for security)
protected $fillable = array('email','school_id','role_id','activation_key','reset_key','login_status','account_status');
// LINK THIS MODEL TO OUR DATABASE TABLE ---------------------------------
protected $table = 'users';
// DEFINE RELATIONSHIPS --------------------------------------------------
public function roles() {
return $this->belongsTo('Role');
}
public function schools() {
return $this->belongsTo('Institution');
}
public function lectures() {
return $this->hasOne('Lecturer');
}
public function students() {
return $this->hasOne('Student');
}
public function getId()
{
return $this->id;
}
}

Answer 1

Let's take a look at Laravel's default User model:
class User extends Eloquent ...
so far so good
... implements UserInterface, RemindableInterface {
Oooops looks like you're missing something ;)
Also the two traits are not unimportant.
Here's how it should look like:
class User extends Eloquent implements UserInterface, RemindableInterface {
use UserTrait, RemindableTrait;
// MASS ASSIGNMENT -------------------------------------------------------
// define which attributes are mass assignable (for security)
protected $fillable = array('email','school_id','role_id','activation_key','reset_key','login_status','account_status');
// [the rest of your model]