cURL error when Integrating the PHP SDK on my project

Hi,

I am Using RingCentral Connect Platform PHP SDK (https://github.com/ringcentral/ringcentral-php) to send fax messages, I get a curl error when i run the script. I have a developer account and testing the authenticate and Fax message and it works fine.

Error details:

Warning: curl_close(): 28 is not a valid cURL handle resource in <path_to_project>vendor
ingcentral
ingcentral-phpsrcHttpClient.php on line 104    Fatal error: Uncaught exception 'InvalidArgumentException' with message 'Invalid response string' in vendor
ingcentralpsr7srcfunctions.php:478  Stack trace:  #0 <path_to_project>vendor
ingcentral
ingcentral-phpsrcHttpApiResponse.php(56): RingCentralPsr7parse_response('HTTP/1.1 0 OK??')  #1 <path_to_project>vendor
ingcentral
ingcentral-phpsrcHttpClient.php(99): RingCentralSDKHttpApiResponse->__construct(Object(RingCentralPsr7Request), false, 0)  #2 <path_to_project>vendor
ingcentral
ingcentral-phpsrcHttpClient.php(25): RingCentralSDKHttpClient->loadResponse(Object(RingCentralPsr7Request))  #3 <path_to_project>vendor
ingcentral
ingcentral-phpsrcPlatformPlatform.php(214): RingCentralSDKHttpClient->send(Object(RingCentralPsr7Request))  #4 <path_to_project>vendor
ingcentral
ingcentral-phpsrcPlatformPlatform.php(301): RingCentralSDKPlatformPlatform->sendReq in C:inetpubwwwrooterexpresspublicvendor
ingcentral
ingcentral-phpsrcHttpClient.php on line 44

Sample code (basically the sample code from - https://github.com/ringcentral/ringcentral-php/blob/master/demo/fax.php):

<?php

use RingCentralSDKSDK;

require_once(__DIR__.'/vendor/autoload.php');

$credentials = require(__DIR__ . '/vendor/ringcentral/ringcentral-php/demo/_credentials.php');

// Authorize

$platform->login($credentials['username'], $credentials['extension'], $credentials['password']);

// Find Fax-enabled phone number that belongs to extension

$phoneNumbers = $platform->get('/account/~/extension/~/phone-number', array('perPage' => 'max'))

->json()->records;

print 'Fax Phone Number: ' . $credentials['username'] . PHP_EOL;

// Send Fax

$request = $rcsdk->createMultipartBuilder()

->setBody(array(

'to' => array(

array('phoneNumber' => $credentials['username']),

),

'faxResolution' => 'High',

))

->add('Plain Text', 'file.txt')

->add(fopen('https://developers.ringcentral.com/assets/images/ico_case_crm.png', 'r'))

->request('/account/~/extension/~/fax');

//print $request->getBody() . PHP_EOL;

$response = $platform->sendRequest($request);

print 'Sent Fax ' . $response->json()->uri . PHP_EOL;