The parameters passed to the API were invalid. Check your inputs!

[jgojariya]

I'm using laravel 4.2. I try bellow example, but it does not work. It occur bellow error.
"The parameters passed to the API were invalid. Check your inputs".

=> Code
$data = array(
'customer' => 'John Smith',
'url' => 'http://laravel.com'
);
Mailgun::send('emails.layout', $data, function($message)
{
$message->to('jgojariya@elluminati.in', 'John Smith')->subject('Welcome!');
});

=> View file code
Hi {{ $customer }},
Please visit {{ $url }}