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 installed Microsoft.Extensions.DependencyInjection.Abstractions assembly successfully.

Then when I tried running my Azure Function project, I got the error Could not load file or assembly Microsoft.Extensions.DependencyInjection.Abstractions.

The exact error message was

A host error has occurred during startup operation ‘e21f9c18-d1ee-4116-8397-67e3017cf895’.
[8/16/2020 7:32:44 AM] TsinfoEmployeCheck: 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.

Could not load file or assembly Microsoft.Extensions.DependencyInjection.Abstractions [Solved]

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

The first thing I have done is, I have uninstalled Microsoft.Extensions.DependencyInjection.Abstractions assembly. Click on the Uninstall button to uninstall Microsoft.Extensions.DependencyInjection.Abstractions assembly.

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

After I installed Microsoft.Azure.Functions.Extensions package, I can 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 tried running the project, I can able to run the project successfully with out any issues.

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• Error While Redeploying The Azure Function System.Exception: Publishing failed

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 the Microsoft.Extensions.DependencyInjection.Abstractions assembly to the project. Hope it will help to fix your issue !!!.