Could not load file or assembly Microsoft.Extensions.DependencyInjection.Abstractions, Version=


After update to the new package Microsoft.EntityFrameworkCore.SqlServer 1.1.2 I got error when try to create DBContext:

System.IO.FileLoadException occurred HResult=0x80131040
Message=Could not load file or assembly 'Microsoft.Extensions.DependencyInjection.Abstractions, Version=, Culture=neutral, PublicKeyToken=adb9793829ddae60' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040) Source=Microsoft.EntityFrameworkCore StackTrace: at Microsoft.EntityFrameworkCore.DbContext..ctor(DbContextOptions options) at Services.Infrastructure.Data.SqlServerDbContext..ctor(DatabaseOptions databaseOptions) in C:\src\backend\Packages\Services.Infrastructure\Data\SqlServerDbContext.cs:line 16 at Translations.Api.Data.TranslationsDbContext..ctor(DatabaseOptions databaseOptions) in C:\src\backend\Modules\Translations\Translations.Api\Data\TranslationsDbContext.cs:line 16

My base DbContext

public class SqlServerDbContext : DbContext
    private readonly DatabaseOptions _databaseOptions;

    protected SqlServerDbContext(DatabaseOptions databaseOptions)
        if (string.IsNullOrEmpty(databaseOptions.ConnectionString))
            throw new Exception("Database connection string is missed.");

        _databaseOptions = databaseOptions;

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)

Database options that I use

public class DatabaseOptions
    public string ConnectionString { get; set; }

Place where I create instance of context

 var dbOptions = new DatabaseOptions { ConnectionString = _connectionString };
 DbContext = (TContext) Activator.CreateInstance(typeof(TContext), dbOptions);
// where TContext is derived class from SqlServerDbContext

All my packages are updated. Visual Studio 2017 15.2 (26430.6). Before upgrade to 1.1.2 everything works fine. Please help to solve the problem.

asked on Stack Overflow May 16, 2017 by Robert N. Dean

9 Answers


Since you're using the project in a .net framework library, there's an issue with auto-generated binding redirects (might be resolved in the upcoming 15.3 update / 2.0 .net core CLI). To work around it, add this in your cpsroj file (preferably before any <Import> element for a .targets file if present):


This should force MSBuild to create / update a YourProject.dll.config file containing the necessary binding redirects.

answered on Stack Overflow May 16, 2017 by Martin Ullrich

I Googled my exception below, and it brought me to this stakoverflow post.

System.IO.FileNotFoundException: 'Could not load file or assembly 'Microsoft.Extensions.OptionsModel, Version=, Culture=neutral, PublicKeyToken=adb9793829ddae60' or one of its dependencies. The system cannot find the file specified.'

I had the relevant Binding Redirects but if I Delete all bin/obj folders it worked fine afterwards.

answered on Stack Overflow Nov 30, 2019 by metoyou

This is an old thread but I had a similar same issue after I updated my Azure function from dotnet core version 3 to 3.1.

Error message: Could not load file or assembly 'Microsoft.Extensions.DependencyInjection.Abstractions, Version=

In this case you need to update the Azure function version to 'v3' in .proj file.

enter image description here

answered on Stack Overflow Oct 15, 2020 by albin • edited Oct 15, 2020 by albin

For me, what did it was to downgrade all the packages support .Net Standard to 2.2.0 from 3.x.x i guess the 3.x packages relevant to a different version of .Net standard which does not support ,net framework.

answered on Stack Overflow Jun 22, 2020 by Yosi Golan

For me the reason was outdated VS. Help > Check for updates > Update. Once updated - the problem was gone.

answered on Stack Overflow Aug 10, 2020 by Giedrius

I updated my packages from NuGet to latest version and working 100%.

answered on Stack Overflow Oct 10, 2020 by mandarin software

I was having this problem. But the packet was Microsoft.Extensions.Primitives. In my case I installed it in my Project and in my Project test from nuget. Maybe could help someone.

answered on Stack Overflow Oct 10, 2020 by Edvan Souza

I had same problem and finally fixed with below solution

  1. Install "System.ComponentModel.Annotations" version 4.4.1 in a temporary project to get the file of "System.ComponentModel.Annotations.dll", then copy this file to your real project and then change your project reference to point this file instead of the original NuGet path

  2. Then in your web.config add below code that redirec

<assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <publisherPolicy apply="no" />
        <assemblyIdentity name="System.ComponentModel.Annotations" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
        <bindingRedirect oldVersion="" newVersion="" />
answered on Stack Overflow Dec 24, 2020 by Leon

If you're working with Azure Functions in .NET Core this will work

If you're not using the .net framework library, but the .net core library, the accepted solution will not work because "you shouldn't be setting the property AutoGenerateBindingRedirects on a netcoreapp project as binding redirects aren't even a thing in netcoreapp, they are only a concept in .NET Framework" (source:

Try this:

  1. Uninstall Microsoft.Extensions.DependencyInjection.Abstractions
  2. Uninstall Microsoft.Extensions.DependencyInjection

Although this seems like a radical solution, it works because the library is already indirectly installed through Microsoft.Azure.Functions.Extensions:

enter image description here

Important: Do not try to solve this issue by upgrading .NET Core from 3.1 to 5.0. Azure functions are not supported in .NET 5.0. A patch is coming in early 2021:

answered on Stack Overflow Jan 3, 2021 by Luis Gouveia

User contributions licensed under CC BY-SA 3.0