AspNetCore Abstractions could not load

Question

I use ASP.NET Core + Angular 2 template for Visual Studio. I have updated my project.json file and it looks now (part of it):

  "dependencies": {
    "Microsoft.AspNetCore.AngularServices": "1.0.0-*",
    "Microsoft.AspNetCore.Authentication.Cookies": "1.1.0-preview1-final",
    "Microsoft.AspNetCore.Diagnostics": "1.1.0-preview1-final",
    "Microsoft.AspNetCore.Hosting.Abstractions": "1.1.0-preview1-final",
    "Microsoft.AspNetCore.Identity": "1.1.0-preview1-final",
    "Microsoft.AspNetCore.Identity.EntityFrameworkCore": "1.1.0-preview1-final",
    "Microsoft.AspNetCore.Mvc": "1.1.0-preview1-final",
    "Microsoft.AspNetCore.Razor.Tools": "1.0.0-preview3-final",
    "Microsoft.AspNetCore.Server.IISIntegration": "1.1.0-preview1-final",
    "Microsoft.AspNetCore.Server.Kestrel": "1.1.0-preview1-final",
    "Microsoft.AspNetCore.StaticFiles": "1.1.0-preview1-final",
    "Microsoft.EntityFrameworkCore": "1.1.0-preview1-final",
    "Microsoft.EntityFrameworkCore.Design": "1.1.0-preview1-final",
    "Microsoft.EntityFrameworkCore.Relational": "1.1.0-preview1-final",
    "Microsoft.EntityFrameworkCore.Relational.Design": "1.1.0-preview1-final",
    "Microsoft.EntityFrameworkCore.Sqlite": "1.1.0-preview1-final",
    "Microsoft.EntityFrameworkCore.SqlServer": "1.1.0-preview1-final",
    "Microsoft.EntityFrameworkCore.SqlServer.Design": "1.1.0-preview1-final",
    "Microsoft.EntityFrameworkCore.Tools": {
      "version": "1.0.0-preview3-final",
      "type": "build"
    },
    "Microsoft.EntityFrameworkCore.Tools.Core": "1.0.0-rc2-final",
    "Microsoft.Extensions.Configuration.CommandLine": "1.1.0-preview1-final",
    "Microsoft.Extensions.Configuration.EnvironmentVariables": "1.1.0-preview1-final",
    "Microsoft.Extensions.Configuration.Json": "1.1.0-preview1-final",
    "Microsoft.Extensions.DependencyInjection.Abstractions": "1.1.0-preview1-final",
    "Microsoft.Extensions.FileProviders.Abstractions": "1.1.0-preview1-final",
    "Microsoft.Extensions.Logging": "1.1.0-preview1-final",
    "Microsoft.Extensions.Logging.Abstractions": "1.1.0-preview1-final",
    "Microsoft.Extensions.Logging.Console": "1.1.0-preview1-final",
    "Microsoft.Extensions.Logging.Debug": "1.1.0-preview1-final",
    "Microsoft.Extensions.Options": "1.1.0-preview1-final",
    "Microsoft.Extensions.Options.ConfigurationExtensions": "1.1.0-preview1-final",
    "Microsoft.Extensions.Primitives": "1.1.0-preview1-final"
  },

  "tools": {
    "Microsoft.AspNetCore.Razor.Tools": "1.0.0-preview2-final",
    "Microsoft.EntityFrameworkCore.Tools": "1.0.0-preview3-final"
  },

  "frameworks": {
    "net461": {}
  },

and when I run an application I got an error:

System.IO.FileLoadException was unhandled
Message: An unhandled exception of type 'System.IO.FileLoadException' occurred in Unknown Module.
Additional information: Could not load file or assembly 'Microsoft.AspNetCore.Hosting.Abstractions, Version=1.0.0.0, 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)

Do you have any idea what is wrong?

Answer 1

Try deleting the bin folder and rebuilding the solution.

Answer 2

Look into the error message carefully. I just installed the NuGet package Microsoft.AspNetCore.Html.Abstractions to the specific project and rebuilt the solution. It resolved the issue for me!