IIS 报错，请问可能是哪个问题。

[rodger_forever]

HTTP Error 500.0 - Internal Server Error
An error message detailing the cause of this specific request failure can be found in the application event log of the web server. Please review this log entry to discover what caused this error to occur. Detailed Error Information
Module AspNetInitClrHostFailureModule
Notification BeginRequest
Handler ScriptHandlerFactory
Error Code 0x80070005
Requested URL http://localhost:80/ILSWebSrv/Page/ILSInterface.asmx
Physical Path E:\WebService\ILSWebSrv_V2\Page\ILSInterface.asmx
Logon Method Not yet determined
Logon User Not yet determined


Most likely causes:
•IIS received the request; however, an internal error occurred during the processing of the request. The root cause of this error depends on which module handles the request and what was happening in the worker process when this error occurred.
•IIS was not able to access the web.config file for the Web site or application. This can occur if the NTFS permissions are set incorrectly.
•IIS was not able to process configuration for the Web site or application.
•The authenticated user does not have permission to use this DLL.
•The request is mapped to a managed handler but the .NET Extensibility Feature is not installed.