Server Error in '/' Application报错。解决方法：右击虚拟文件夹，选择“转换成应用程序” 

Server Error in '/' Application.

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Runtime Error

Description: An application error occurred on the server. The current custom error settings for this application prevent the details of the application error from being viewed remotely (for security reasons). It could, however, be viewed by browsers running on the local server machine.

Details: To enable the details of this specific error message to be viewable on remote machines, please create a <customErrors> tag within a "web.config" configuration file located in the root directory of the current web application. This <customErrors> tag should then have its "mode" attribute set to "Off".

<!-- Web.Config Configuration File --> <configuration> <system.web> <customErrors mode="Off"/> </system.web> </configuration>

Notes: The current error page you are seeing can be replaced by a custom error page by modifying the "defaultRedirect" attribute of the application's <customErrors> configuration tag to point to a custom error page URL.

<!-- Web.Config Configuration File --> <configuration> <system.web> <customErrors mode="RemoteOnly" defaultRedirect="mycustompage.htm"/> </system.web> </configuration>

 解决方案： 

 添加了虚拟目录后，右击虚拟文件夹，选择“转换成应用程序” （convert  to application）就OK了。

 其他建议：

先用本机的 IIS 测试，不要用 VS 内附的 Web server，

並配置 <customErrors mode="Off"/>，以將真實的錯誤原因顯示出來，看是否仍会一样出错。

有可能是文件夹未开放写入权限，或有安全配置上的错误。

或远端机器上 IIS 的 .NET 版本、ajax 版本不符合。