错误为500时，表示它是内部错误，表示服务内部-服务引发了未被捕获的异常.
在服务上的 Windows事件日志中查看问题出在哪里.

另外，请尝试:
-在IE中转到菜单工具/Internet选项".
-单击高级"选项卡上的取消选中显示友好的HTTP错误消息"选项，然后单击确定".
-尝试再次访问您的网页.现在，您将看到更有意义的错误消息，它将帮助您解决问题.

其他可能性:
您托管服务的方式可能存在问题.可能是多个配置文件?

When the error is 500, that means it''s an internal error, meaning internal to the service - the service threw an exception that was not caught.
Look in the Windows event logs on the service to see what went wrong.

Also, try:
- Go to menu Tools/Internet Options in your IE.
- Click on the Advanced tab, uncheck "Show friendly HTTP error messages" option and click Ok.
- Try accessing your web page again. Now you will see much more meaningful error message which will help you to troubleshoot the problem.

Other possibility:
There might be an issue in the way you have hosted your service. May be multiple config files?

由于错误500是一般性错误，对于实际问题并没有多大帮助，我建议您在Web服务中使用 try..catch blocks获取有关问题根源的信息.

Since error 500 is a generic error and doesn''t tell much about the actual problem, I suggest that you use try..catch blocks in your web services the get information abuot the root cause of the problem.