SoapFault in Service.php line 218: Index: 1, Size: 1

i am using artisaninweb/laravel-soap in laravel 5.1, and i am getting the error SoapFault in Service.php line 218: Index: 1, Size: 1

SoapWrapper::service('getAvailability', function ($service) use ($data) { 
      var_dump($service->getFunctions());
      dd($service->call('getAvailability', $data)->getAvailabilityResult);   
});

i am struct here, whats going wrong i dont know.

via Chebli Mohamed