appache 问题

用APPACHE2.2版本与KARRIGELL结合。成功了，后来我重装了系统，
重新按照原来的方式配置，结果出现入下错误：

Proxy Error
The proxy server received an invalid response from an upstream server.
The proxy server could not handle the request GET /.

Reason: Max-Forwards has reached zero - proxy loop?


Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.

怎么解决呀？

是Apache，不是APPACHE

贴出你的配置