什么导致 XML Parsing Error: no root element found 错误？

Question

我最近开始在 Firebug 中显示以下错误：

XML 解析错误：找不到根元素位置：http://dd.example.com/1.0/sources/30 第 1 行第 1 列：30:1:1

是什么原因造成的，我该如何解决？

标题标签：

Request URL: http://dd.example.com/1.0/sources/30
Request Method: PUT
Remote address: 11.11.111.111:80
Status Code: 204 No Content
Version: HTTP/1.1

请求标头：

Host: dd.example.com
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:51.0) Gecko/20100101 Firefox/51.0
Accept: */*
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Referer: http://dd.example.com/
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
X-Requested-With: XMLHttpRequest
Content-Length: 33
Cookie: _ga=GA1.2.1885184115.1475238275; PHPSESSID=7ggri150scu2g5et1f7gtone94
Authorization: Basic TEljaGGlcDqTdW5zaKfrZX==
Connection: keep-alive

请求正文：

name=name&value=Remote+Sock&pk=30

响应标头：

Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Connection: close
Content-Length: 0
Content-Type: 
Date: Sun, 05 Feb 2017 16:59:50 GMT
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Pragma: no-cache
Server: Apache/2.2.15 (CentOS)
X-Powered-By: PHP/5.

Answer 1

正在发送状态码 204，但正在尝试发送内容。