Php 未捕获的SoapFault异常：[soap:Server]服务器无法处理请求

我使用以下PHP代码：

<?php 
ini_set("soap.wsdl_cache_enabled", "0");

$AccountShabaCode   = "123456789012345678900000";
$WorkTitle          = "Example";
$GuildCode          = "48160000";
$PardakhtYarTitle   = "Xxxa";

$soapclient = new SoapClient('http://87.107.134.111:8021/PardakhtYar.asmx?wsdl');

$add_new_request = $soapclient->AddNewRequest(array('AccountShabaCode' => $AccountShabaCode, 'Password' => $Password, 'WorkTitle' => $WorkTitle, 'GuildCode' => $GuildCode, 'PardakhtYarTitle' => $PardakhtYarTitle));

print_r($add_new_request);
?>

如何修复此错误

我需要打电话“AddNewRequest”（）

Fatal error:  Uncaught SoapFault exception: [soap:Server] Server was unable to process request. ---> Object reference not set to an instance of an object. in C:\WAMP\home\example.tld\public_html\test.php:11
Stack trace:
#0 C:\WAMP\home\example.tld\public_html\test.php(11): SoapClient->__call('AddNewRequest', Array)
#1 {main}
  thrown in C:\WAMP\home\example.tld\public_html\test.php on line 11