HTTP Error 500.19 – Internal Server Error The requested page cannot be accessed because the related configuration data for the page is invalid.

问题描述：

HTTP Error 500.19 - Internal Server Error
The requested page cannot be accessed because the related configuration data for the page is invalid.

Detailed Error Information:
Module	   IIS Web Core
Notification	   BeginRequest
Handler	   Not yet determined
Error Code	   0x80070021
Config Error	   不能在此路径中使用此配置节。如果在父级别上锁定了该节，便会出现这种情况。锁定是默认设置的(overrideModeDefault="Deny")，或者是通过包含 overrideMode="Deny" 或旧有的 allowOverride="false" 的位置标记明确设置的。
Config File	   \\?\G:\source\cloud\cloudpos\src\SissCloud.Website\web.config
Requested URL	   http://dev-sy-zx.sixun.com.cn:80/
Physical Path	   G:\source\cloud\cloudpos\src\SissCloud.Website
Logon Method	   Not yet determined
Logon User	   Not yet determined

Config Source:
   93:     <validation validateIntegratedModeConfiguration="false"/>
   94:     <handlers>
   95:       <remove name="ExtensionlessUrlHandler-ISAPI-4.0_32bit"/>

More Information:
This error occurs when there is a problem reading the configuration file for the Web server or Web application. In some cases, the event logs may contain more information about what caused this error.
View more information »

解决方案：

定位到：开始->控制面板->程序->启用或关闭windows功能（新版本windows控制面板隐藏有点深，可点击windows开始进行搜索“控制面板”切回旧的控制面板视图）

下图以windows 10为例：

在 启用或关闭windows功能列表中，可选择两者其一：

选项A ：勾选“.NET Framework 3.5(包括.NET2.0和3.0)” 及 Internet Information Services->万维网服务->应用程序开发功能->ASP.NET3.5与.NET Extensibility 3.5

选项B：勾选“.NET Framework 4.8 Advanced Services->ASP.NET4.8” 及 Internet Information Services->万维网服务->应用程序开发功能->ASP.NET4.8与.NET Extensibility 4.8

原文链接：HTTP Error 500.19 – Internal Server Error The requested page cannot be accessed because the related configuration data for the page is invalid.