Server Application Unavailable

IIS上面所有的webservices都出现异常，异常代码：

The web application you are attempting to access on this web server is currently unavailable.  Please hit the "Refresh" button in your web browser to retry your request.

Administrator Note: 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. 

访问权限的问题：

重新新建一个应用程序池，将webservices的应用程序池修改为新增的即可解决。