After I updated vs2017 to the latest version this morning and uninstalled vs2019 Enterprise Preview (v16.0) and installed vs2019 Enterprise (v16.1), and installed the latest Windows updates all .NET Core 2.0.0 website no longer starting.
HTTP Error 500.19 - Internal Server Error The requested page cannot be accessed because the related configuration data for the page is invalid.
Complaining about web.config file:
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<location path="." inheritInChildApplications="false">
<system.webServer>
<handlers>
<add name="aspNetCore" path="*" verb="*" modules="AspNetCoreModule" resourceType="Unspecified" />
</handlers>
<aspNetCore processPath="dotnet" arguments=".\Sitecore.IdentityServer.Host.dll" stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" />
</system.webServer>
</location>
</configuration>
<!--ProjectGuid: 411a84e3-bdaa-45d8-89a2-b47670e591eb-->
Specifically regarding this element:
System.Runtime.InteropServices.COMException (0x80004005): Line number: 10 Error: The configuration section 'system.webServer/aspNetCore' cannot be read because it is missing section definition