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

Question

Before everyone reads this, I just want to say that i know that there are related threads out there, but I have either tried them or do not understand. With that being said here

Answer 1

For completeness, the answer to Asp.Net Core tag in web.config causes failure may also be the solution to the problem here. If the .NET Core Windows Server Hosting bundle is not installed then IIS cannot recognize the aspNetCore section in web.config. https://docs.microsoft.com/en-us/aspnet/core/host-and-deploy/iis/?view=aspnetcore-3.1#install-the-net-core-hosting-bundle claims to be a direct download to the current version.

Answer 2

I had this error with Visual Studion 2019, my project was NopCommerce 4.30 which is an ASP.Net Core 3.1 project. I added page "gouden-munten-buitenland" to be the starting page and I only got the error when going to that page. Turned out that Visual Studio generated an invalid applicationHost.config :

<applicationPools>
    ....
    <add name="gouden-munten-buitenland AppPool" autoStart="true" />
    <add name="gouden-munten-buitenland AppPool 2" autoStart="true" /> <!-- WRONG -->
    <add name="Nop.Web AppPool" managedRuntimeVersion="" />
    <applicationPoolDefaults managedRuntimeVersion="v4.0">
    <processModel loadUserProfile="true" setProfileEnvironment="false" />
    </applicationPoolDefaults>
</applicationPools>

and

<sites>
    ....
    <site name="Nop.Web" id="2">
    ...
    <application path="/gouden-munten-buitenland/gouden-munten-buitenland" applicationPool="gouden-munten-buitenland AppPool">
        <virtualDirectory path="/" physicalPath="C:\Usr\Stephan\Wrk\Kevelam\kNop.430\Presentation\Nop.Web" />
    </application>
    <application path="/gouden-munten-buitenland" applicationPool="gouden-munten-buitenland AppPool 2">
        <virtualDirectory path="/" physicalPath="C:\Usr\Stephan\Wrk\Kevelam\kNop.430\Presentation\Nop.Web" />
    </application> <!-- WRONG -->
    ....
    </site>
    ...
</sites>

I removed the nodes identified as 'WRONG' and then it worked.

Answer 3

Goto Windows Features on or Off . Enable All Features under Application Development Features and Refresh the IIS. Its Working

Answer 4

Delete .vs/Config folder => work for me