Curl to test Sabre REST API Authentication Failing - php

Question

I'm creating the authentication and getting an access token fine but the problem arises when I try to send a request. I'm creating the headers using PHP
<?php
define("POST", "POST");
**$environment=' https://api-crt.cert.havail.sabre.com';**
$userId='XXXXXXX';
$domain='AA';
$Group='XXXXXXXXXX';
$formatVersion='V1';
$clientSecret=base64_encode('XXXXXXXXXXX');
$client_id=base64_encode($formatVersion.":".$userId.":".$Group.":".$domain);
$bulid_credential=base64_encode($client_id.":".$clientSecret);
######################## Step 1: Get Token #############################
**$ch =curl_init("https://api-crt.cert.havail.sabre.com/v2/auth/token");**
$vars ="grant_type=client_credentials";
$header =array(
'Authorization: Basic '.$bulid_credential,
'Accept: */*',
'Content-Type: application/x-www-form-urlencoded'
);
curl_setopt($ch, CURLOPT_HTTPHEADER, $header);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_VERBOSE, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
curl_setopt($ch, CURLOPT_POSTFIELDS, $vars);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$res= curl_exec($ch);
$result=json_decode($res);
$token=$result->access_token;
########################## Step 2: Call the REST API###################
**$url="https://api.test.sabre.com/v3.3.0/shop/flights?mode=live";**
$header = array(
'Authorization: Bearer'. $token,
'Content-Type: application/json'
);
$calltype='POST';
$ch = curl_init();
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, $calltype);
curl_setopt($ch, CURLOPT_VERBOSE, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_POSTFIELDS, $jsonrequest);//Request
array_push($header, 'Content-Type: application/json');
curl_setopt($ch, CURLOPT_HTTPHEADER, $header);
$result=curl_exec($ch);
$result1=json_decode($result);
curl_close($ch);
?>
The Sabre Response :
{"status":"Incomplete","type":"Application","errorCode":"ERR.2SG.PROVIDER_ERROR","timeStamp":"2017-10-11T06:02:08.658-05:00","message":"Error occurred while invoking service rest:readMetadata:1.13.7.SNAPSHOT"}

Answer 1

1) Did you ensure that $token is a string and not an object?
I use this:
$result=json_decode($res, TRUE);
$token=$result['access_token'];
Instead of this:
$result=json_decode($res);
$token=$result->access_token;
2) Did you ensure that the content of $jsonrequest is valid?
Maybe it's not the PHP code that is incorrect, but your JSON query.