Catchable Fatal Error: Argument 4 passed to UsernamePasswordToken::__construct() must be an array, null given

Basically, what the error message says is:

The 4th argument for UsernamePasswordToken::__construct() should be an array, but it's null. It was called in UserAuthenticationProvider at line 96.

If you take a look at that code, you'll see that the 4th argument for UsernamePasswordToken::__construct() is $roles. So that should be an array, but it's getting null instead.

I'm guessing that you have written your own User entity, and that the getRoles() method of your user entity is returning null instead of an array of roles. So just change that method to something like this:

/**
 * Returns the roles granted to the user.
 * 
 * @return Role[] The user roles
 */
public function getRoles()
{
    return array('ROLE_USER');
}

Of course, the actual code may differ (you might want to store the user roles in the database), as long as getRoles() returns an array of strings or Role objects.

I fix this error so returning roles:

public function getRoles()
{
    return $this->roles->toArray();

}