Could not load file or assembly Microsoft.Extensions.DependencyInjection.Abstractions

In this Azure tutorial, we will discuss how to fix the error, Could not load file or assembly Microsoft.Extensions.DependencyInjection.Abstractions. This error I got this while running an Azure function dependency Injection project using Visual Studio 2019 on my local machine.

Could not load file or assembly Microsoft.Extensions.DependencyInjection.Abstractions

I have an Azure Function project where I am trying to implement the Dependency Injection as well. I have referred to Microsoft.Extensions.DependencyInjection.Abstractions assembly to the project by installing that from the Nuget Package following the below steps

Right-click on the Project —> Manage Nuget Packages and then search for Microsoft.Extensions.DependencyInjection.Abstractions and then click on the Install button.

Then I clicked on the I Accept button from the below pop-up to accept the License acceptance.

Now it has installed Microsoft.Extensions.DependencyInjection.Abstractions assembly successfully.

Then when I tried running my Azure Function project, I got this error.

The exact error message was

A host error has occurred during startup operation ‘e21f9c18-d1ee-4116-8397-67e3017cf895’. Could not load file or assembly ‘Microsoft.Extensions.DependencyInjection.Abstractions, Version=3.1.7.0, Culture=neutral, PublicKeyToken=adb9793829ddae60’. The system cannot find the file specified. System.Private.CoreLib: Could not load the specified file.

Solution

Now to fix this issue, I have followed the below steps

1. The first thing I did was uninstall Microsoft.Extensions.DependencyInjection.Abstractions assembly. Click on the Uninstall button to uninstall Microsoft.Extensions.DependencyInjection.Abstractions assembly.

2. Install the Microsoft.Azure.Functions.Extensions assembly instead of the Microsoft.Extensions.DependencyInjection.Abstractions assembly. Search for the Microsoft.Azure.Functions.Extensions assembly and then click on the install button to install it. The Microsoft.Azure.Functions.Extensions assembly also references the Microsoft.Extensions.DependencyInjection. Abstractions package.

3. After I installed the Microsoft Azure Functions Extensions package, I was able to run the Azure Functions project successfully without any issues.

Here is my Azure function code

using System;
using System.IO;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json;
using System.Linq;

namespace TsinfoEmployeCheck
{
    public  class Function2
    {
        private readonly IEmployeeService employeeService;
        public Function2(IEmployeeService employeeService)
        {
            this.employeeService = employeeService;
        }
        [FunctionName("TsinfoEmployeCheck
")]
        public  async Task<IActionResult> Run(
            [HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)] HttpRequest req,
            ILogger log)
        {
            log.LogInformation("C# HTTP trigger function processed a request.");

           
            string empemail123 = req.Query["EmailID"];

            string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
            dynamic data = JsonConvert.DeserializeObject(requestBody);
            empemail123 = empemail123 ?? data?.empemail123;

           
        string response = employeeService.EmployeeEmail(empemail123);
                return response == "Valid EmailID"
                ? (ActionResult)new OkObjectResult($"TSINFO Valid Employee belongs to TSINFO")
                : new BadRequestObjectResult("Invalid Employee.Not belongs to the TSINFO");

          
        }
    }
}

Now, when I try running the project, I am able to run it successfully without any issues.

Conclusion

Well, in this article, we discussed how to fix the error “Could not load file or assembly Microsoft.Extensions.DependencyInjection.Abstractions” that I got while trying to run my Azure Function project after referring to the Microsoft.Extensions.DependencyInjection.Abstractions assembly to the project. I hope it will help to fix your issue!!!

Bijay Kumar

I am Bijay, a Microsoft MVP (10 times) having more than 17 years of experience in the software industry. During my IT career, I got a chance to share my expertise in SharePoint and Microsoft Azure, like Azure VM, Azure Active Directory, Azure PowerShell, etc. I hope you will learn from these Azure tutorials. Read more