错误信息 ： There was an error processing the request

服务器环境：Win 2003 / IIS6 / ASP.NET AJAX 1.0 / C# 2.0

使用ASP.NET AJAX 1.0开发的一个网站，在页面提交的时候会出现如下错误信息。

There was an error processing the request

在网上搜索了一下找到了

http://dotnetslackers.com/columns/ajax/AspNetAjaxExceptionLogging.aspx

Another interesting thing I found when working with client exceptions is, when a server side exception (Web Service, Update Panel) is generated you will find the actual exception message, type, stack trace of that exception in JavaScript. Once you set the customErrors mode to On in the web.config file (recommended) when deploying the website, you'll obtain the generic message "There was an error processing the request" and no exception type and stack trace. I think this is unfortunate; at least the exception message and type should be present on the client side. May be the ASP.NET AJAX Team will consider this in future release.

解决的方法很奇怪。

需要设置 web.config 中的customErrors为Off

<customErrors mode="Off">

具体原因不清楚。

有了解这方面信息的吗？