Marketo REST API-更新登录页模板-系统错误611

我尝试使用（Marketo-doc-page:）上的PHP示例代码段，通过替换我的REST API URL、client_Id、client_secret和一个简单的模板文件，按Id更新登录页模板内容。其结果只是产生bool（false）。

当我使用稍微不同的等价物时，我发现我的REST调用导致…对象（stdClass）#3（3）｛["requestId"]=>字符串（16）"e714#153c7bf644f"["success"]=>bool（false）["errors"]=>数组（1）｛[0]=>对象（stdClass）#4（2）｛〔"code"〕=>字符串（3）"611"["message"]=>string（12）"System error"｝｝}

神秘的错误代码611是怎么回事——它的真正含义是什么，因为"系统错误"没有足够的帮助来知道——为什么会在这种情况下发生？

这个用于更新登陆页模板的REST API是否仍然有效？

<?php
/*
  Some other functions that made use of $lp_template_id are up here
*/
$landingPageTemplate = new UpdateLandingPageTemplateContent();
$landingPageTemplate->id = 1234;
$landingPageTemplate->content = new CURLFile("/path_to_my_template/{$lp_template_id}", "text/html", "content");
print_r($landingPageTemplate->postData());
class UpdateLandingPageTemplateContent{
    private $host = "https://xxx-xxx-xxx.mktorest.com";
    private $clientId = "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx";
    private $clientSecret = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
    public $id;//id of the teplate to update
    public $content; //HTML content of Template, required
    public function postData(){
        $url = $this->host . "/rest/asset/v1/landingPageTemplate/" . $this->id . "/content.json?access_token=" . $this->getToken();
        $ch = curl_init($url);
        $requestBody = array("content" => $this->content);
        curl_setopt($ch,  CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_HTTPHEADER, array('accept: application/json','Content-Type: multipart/form-data'));
        curl_setopt($ch, CURLOPT_POST, 1);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $requestBody);
        curl_getinfo($ch);
        $response = curl_exec($ch);
        return $response;
    }
    private function getToken(){
        $ch = curl_init($this->host . "/identity/oauth/token?grant_type=client_credentials&client_id=" . $this->clientId . "&client_secret=" . $this->clientSecret);
        curl_setopt($ch,  CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_HTTPHEADER, array('accept: application/json',));
        $response = json_decode(curl_exec($ch));
        curl_close($ch);
        $token = $response->access_token;
        return $token;
    }
}