Invalid Request error was encountered while trying to process the request:
%R
Some possible problems are:
要求方式遺失或是未知
網站位置遺失
HTTP 標準的宣告遺失（HTTP/1.0）
要求命令過長
Content-Length missing for POST or PUT requests.
欲連結的主機名稱包含不合法的字元；底線這個字元是不被允許存在的。
HTTP/1.1
Expect:
feature is being asked from an HTTP/1.0 software.
Your cache administrator is %w.