Facebook Login Asp.net Mvc Object reference not set to an instance of an object

I'm learning asp.net mvc.I'm trying to do sample application with visual studio mvc template. Login system ok for google but i have problem about signing with facebook account. At the first step is done. I'm redirected Associate your Facebook account page. When i entered my Username and click the button i'm getting Object reference not set to an instance of an object for "info" variable at the blow code. ``` public async Task<ActionResult> ExternalLoginConfirmation(ExternalLoginConfirmationViewModel model, string returnUrl) { if (User.Identity.IsAuthenticated) { return RedirectToAction("Manage"); } if (ModelState.IsValid) { // Get the information about the user from the external login provider var info = await AuthenticationManager.GetExternalLoginInfoAsync(); if (info == null) { return View("ExternalLoginFailure"); } var user = new ApplicationUser() { UserName = model.UserName }; var result = await UserManager.CreateAsync(user); if (result.Succeeded) { result = await UserManager.AddLoginAsync(user.Id,info.Login); if (result.Succeeded) { await SignInAsync(user, isPersistent: false); return RedirectToLocal(returnUrl); } } AddErrors(result); } ViewBag.ReturnUrl = returnUrl; return View(model); } ```