Could not load file or assembly 'System.Diagnostics.DiagnosticSource on ASP.Net Core migration from VS2015 to VS2017

Question

I have a web in ASP.Net Core (4.6.1 framework) that uses Facebook and MS external login that I created with Visual Studio 2015 and opened in the new Visual Studio 2017 that came out yesterday. VS2017 made a few changes related to the csproj, project.json, etc files.

The site compiled and executed fine except for one part. If I did a Facebook or Microsoft external login, the site displayed this trap:

FileLoadException: Could not load file or assembly 'System.Diagnostics.DiagnosticSource, Version=4.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

System.Net.Http.WinHttpHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
AggregateException: Unhandled remote failure.

Microsoft.AspNetCore.Authentication.RemoteAuthenticationHandler+<HandleRemoteCallbackAsync>d__6.MoveNext()

The url in the browser showed that it was attempting to return from the external login to the local ( https://localhost:44321/signin-facebook?code= ... or /signin-microsoft).

The version number of the System.Diagnostics.DiagnosticSource.dll (and System.Net.Http.dll) is 4.6.24705.1.

I started a new VS2017 project from scratch with Facebook and MS login added and it worked fine - getting me logged on without the trap. The dll's were the same versions.

Comparing the two csproj files showed differences but nothing obvious (nothing related to System dlls):

Answer 1

What solved it for me was to add a NuGet reference to System.Net.Http (version 4.3.1) to the newly migrated project. https://www.nuget.org/packages/System.Net.Http/

Answer 2

The recommended answer did not resolve my issue. I was getting this error when trying to reference a .Net 4.6.2 lib in a .Net Core 2 project.

To resolve the issue I had to add the Microsoft.Windows.Compatibility nuget package. Credit to: https://medium.com/@ans_ashkan/asp-net-core-and-windows-event-log-75770a80a666

Answer 3

In References 'System.Diagnostics.DiagnosticSource' not included in solution

On installing latest version "5.0.1" of 'System.Diagnostics.DiagnosticSource' in NUget solved my issue. Hope it will fix yours also.

Answer 4

People using .NET Core web applications monitored with Application Insights hosted in App Services facing this issue

This when .NET Core web application has a dependency on 'System.Diagnostics.DiagnosticSource%u2019 binary and has this binary file deployed to /wwwroot/ folder, which is rare.

Work Around: Please set previous version of monitoring extension by changing this app setting if you experience the above issue: ApplicationInsightsAgent_EXTENSIONVERSION=2.8.24

After doing this please restart the application.

Here is the source

Answer 5

I had the same issue and weirdly enough, problem resolved with updating Microsoft.ApplicationInsights versions. 2.20.0 is the version to go (for me). I don't know the connection between these packages but that's what happened.