Error in Azure Web App Virtual Directory: "Could not load file or assembly 'Microsoft.AspNet.TelemetryCorrelation' or one of its dependencies."

[BryanWilhite]

In an Azure Virtual Directory with just index.html and a minimal Web.config throws this error:

Could not load file or assembly 'Microsoft.AspNet.TelemetryCorrelation' or one of its dependencies.

This error is thrown when navigating to / instead of /index.html. An error will occur when Web.config is not present (but no error message is shown).

The parent/root application is, of course, configured for App Insights telemetry. Is this expected behavior for an expected error condition? Do we need to have App Insights installed for every Virtual Directory?

BTW: this is the minimal Web.config:

<configuration>
    <system.web>
        <customErrors mode="Off"/>
    </system.web>
</configuration>

[SergeyKanzhelev]

@BryanWilhite few questions:

• what framework you application was compiled against?
• where app deployed? Local IIS or Azure Web App?
• was Application Insights enabled from Visual Studio or using Status Monitor or Azure WebApp extension?

[BryanWilhite]

@SergeyKanzhelev this was on Azure configured for .NET and Application Insights was enabled from Visual Studio.

[SergeyKanzhelev]

So you enabled Application Insights and then cleaned up web.config? Or config wasn't properly updated?

BTW, do you call Application Insights explicitly? If not - I wonder how it got initialized at all without the mention of Application Insights http module there.

(What FW version? 4.6?)

[BryanWilhite]

steps to repeat:

• set up a root Web App in Azure with Application Insights
• add virtual directory, /foo, under the root Web App with the index.html and Web.config mentioned above

I expect that going to /foo would just display index.html. This is not happening for me.

[SergeyKanzhelev]

@clguimanMSFT, @iusafaro can you please take a look

[clguiman]

@BryanWilhite What do you mean by "set up a root Web App in Azure with Application Insights"?
Did you click on "Configure Application Insights" from the project contextual menu in Visual Studio? Or did you select an Application Insights resource when publishing the Web App?

[SergeyKanzhelev]

I believe @BryanWilhite means something like this https://blogs.msdn.microsoft.com/tomholl/2014/09/21/deploying-multiple-virtual-directories-to-a-single-azure-website/. Bryan, correct me if I'm wrong

[BryanWilhite]

Let's go with click on "Configure Application Insights" from the project contextual menu in Visual Studio; let's assume the simplest Visual-Studio-based scenario so misunderstanding does not run wild.

[Guiroux555]

I have the same problem. I have an ASP.NET WebSite with ApplicationInsight installed and a virtual application configured. A simple html file in the application. If i load the file with absolute URL, it work but not if i load the racine of the virtual application

[vikram77]

@BryanWilhite i had the same issue and a quick workaround was to add Microsoft.AspNet.TelemetryCorrelation package to the virtual application. This resolved the issue for me. Hope that works for you.

[Michaelvsk]

Hi,

any updates on this topic? Currently facing the exact same problem. I have a ASP.NET (.NET Framework) based application using AppInsights deployed to the root virtual application and a NodeJS App running inside another virtual application using AppInsights, too.
Both work when deployed to seperate app services but when using a virtual application, I get the same error as Bryan for the non-root virtual app.

[SergeyKanzhelev]

@clguimanMSFT @Mikhail-Pranovich can you please confirm that the next release with the global module will address this issue? If not - can you please track this issue and give updates?

[Mikhail-msft]

@SergeyKanzhelev, the issue is not related to WebApps ApplicationInsights extension, and is not related to ApplicationInsights SDK. According to repro I saw this is purely within 'Microsoft.AspNet.TelemetryCorrelation' where if it is used in web.config of root application, the subapplication would try to load it as well.

[denisky]

Hi,
I had the same issue, our root web site is using ASP.NET MVC with ApplicationInsights and a virtual application in Vue.js.

My solution was to add the following to the Web.Config:

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
  <system.webServer>
    <modules runAllManagedModulesForAllRequests="false">
      <remove name="TelemetryCorrelationHttpModule" />
      <remove name="ApplicationInsightsWebTracking" />
    </modules> 
  </system.webServer>
</configuration>

[ptorkaman]

Hi,
i had same problem and i install with nuget package manages and brows Microsoft.AspNet.TelemetryCorrelation and installed it

[jwisener]

Is this still an on going issue for over 3 years now?

[boyukbas]

Hi,
I had the same issue, our root web site is using ASP.NET MVC with ApplicationInsights and a virtual application in Vue.js.

My solution was to add the following to the Web.Config:

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
  <system.webServer>
    <modules runAllManagedModulesForAllRequests="false">
      <remove name="TelemetryCorrelationHttpModule" />
      <remove name="ApplicationInsightsWebTracking" />
    </modules> 
  </system.webServer>
</configuration>

I was having a similar problem and that worked for me. Thanks

[jordanrbaker]

@Mikhail-msft - FYSA, this bug still exists and was observed on 04/20/2022.

The solution offered by @boyukbas was successful in resolving our issue.

[raelshark]

Still the same in Dec 2023. Virtual applications under Azure App Service web apps using TelementryCorreletion also try to load this library.

I also solved it with the modules config solution from denisky above. Doesn't seem like it should be necessary.