2.2.0 IIS Hosting Bundle 500.30 error when setting web.config ASPNETCORE_ENVIRONMENT

Describe the bug

We get a HTTP Error 500.30 - ANCM In-Process Start Failure after upgrading to asp.net core 2.2

To Reproduce

Steps to reproduce the behavior:

1. Install the latest Windows 2.2.0 hosting bundle (aspnetcore.dll 12.2.18316) on Windows server
2. Create an asp.net core 2.2 web app with inprocess hosting
3. Add a web.config:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <!-- To customize the asp.net core module uncomment and edit the following section. 
  For more info see https://go.microsoft.com/fwlink/?linkid=838655 -->
  <system.webServer>
    <handlers>
      <remove name="aspNetCore" />
      <add name="aspNetCore" path="*" verb="*" modules="AspNetCoreModuleV2" resourceType="Unspecified" />
    </handlers>
    <aspNetCore processPath="%LAUNCHER_PATH%" arguments="%LAUNCHER_ARGS%" stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" hostingModel="InProcess"/>
  </system.webServer>
</configuration>

1. Run the site using IIS Express
2. Verify environment variables were added to your web.config:

<aspNetCore processPath="%LAUNCHER_PATH%" arguments="%LAUNCHER_ARGS%" stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" hostingModel="InProcess">
      <environmentVariables>
        <environmentVariable name="ASPNETCORE_HTTPS_PORT" value="44368" />
        <environmentVariable name="ASPNETCORE_ENVIRONMENT" value="Development" />
      </environmentVariables>
    </aspNetCore>

1. On the server, create the site in IIS and then set an ASPNETCORE_ENVIRONMENT variable in machine-wide IIS applicationhost.config for the site
2. Publish to the server and hit the site
3. See the error
4. I verified that if I remove the web.config environmentVariable named ASPNETCORE_ENVIRONMENT the site loads. Adding other web.config environment variables does not cause any problems.

Expected behavior

The site should start

Additional context

We set our ASPNETCORE_ENVIRONMENT environment variables for our sites in IIS applicationhost.config. I got the error for a site with “STAGING” set in applicationhost.config. I verified that even if I set the same value to “STAGING” in web.config the site will not start.

We use shared applicationhost.config, but I don’t think that’s pertinent.

The issue could obviously be duplicated without running the site in IIS Express first - as long as the ASPNETCORE_ENVIRONMENT variable is in web.config the site will not be able to startup on the server if that variable is also set in applicationhost.config. I have not confirmed that the site works if there is no ASPNETCORE_ENVIRONMENT variable set for the site in applicationhost.config.

If there is no web.config in the Visual Studio project or if a default one is added which is all commented out a web.config is not created or modified when running the site in IIS Express.

This did not error in asp.net core 2.1.

I enabled logging in web.config and added a logs folder and a stdout logfile was created but it was empty.

I worked around this by removing the environment variable from web.config before publishing.

Cross-reference: https://github.com/aspnet/Docs/issues/10046

[mokth]

just go cmd, go to u side folder. run dotnet <u api.dll> as u found on the web.config. then u will found what error. for me… it the damm shit connection string the "", need to put “\”

[guardrex]

@pakrym Just want to make sure you see 👁️ this.