How to fix your login to load when using ASP.NET MVC?

// GET: /Account/Login
[AllowAnonymous]
public ActionResult Login(string returnUrl)
{
    TempData["ErrorMessage"] = "";
    TempData["LoginMessage"] = "";
    ViewBag.ReturnUrl = returnUrl;
    return View();
}

//
// POST: /Account/Login
[HttpPost]
[AllowAnonymous]
[ValidateAntiForgeryToken]
public async Task<ActionResult> Index(LoginViewModel model, string returnUrl)
{
    if (!ModelState.IsValid)
    {
        return View(model);

    }

    var emailExist = await UserManager.FindByEmailAsync(model.Email);
    if(emailExist != null)
    {
        if(emailExist.EmailConfirmed == false)
        {
            string code = await UserManager.GenerateEmailConfirmationTokenAsync(emailExist.Id);
            var callbackUrl = Url.Action("ConfirmEmail", "Account", new { userId = emailExist.Id, code = code }, protocol: Request.Url.Scheme);
            await UserManager.SendEmailAsync(emailExist.Id, "Confirm your account", ConfirmAccountMailBody(callbackUrl));

            TempData["ErrorMessage"] = "Email id is not verified. Please check your email and verify account !!!";
            ViewBag.JavaScriptFunction = "ShowErrorPopup();";
            return View(model);
        }
    }
    else
    {
        TempData["ErrorMessage"] = "Email is not registered !!!";
        ViewBag.JavaScriptFunction = "ShowErrorPopup();";
        return View(model);
    }

    var loggedinUser = await UserManager.FindAsync(model.Email, model.Password);
    if(loggedinUser !=null)
    {
        await UserManager.UpdateSecurityStampAsync(loggedinUser.Id);
    }

    // This doesn't count login failures towards account lockout
    // To enable password failures to trigger account lockout, change to shouldLockout: true
    var result = await SignInManager.PasswordSignInAsync(model.Email, model.Password, model.RememberMe, shouldLockout: false);
    switch (result)
    {
        case SignInStatus.Success:
            return RedirectToLocal(returnUrl);
        case SignInStatus.LockedOut:
            return View("Lockout");
        case SignInStatus.RequiresVerification:
            return RedirectToAction("SendCode", new { ReturnUrl = returnUrl, RememberMe = model.RememberMe });
        case SignInStatus.Failure:
        default:
            TempData["ErrorMessage"] = "Email or Password is Incorrect";
            ViewBag.JavaScriptFunction = "ShowErrorPopup();";
            return View(model);
    }
}

// Route to Login.
         routes.MapRoute(
            name: "Login",
            url: "login/",
            defaults: new { controller = "Account", action = "Index", id = UrlParameter.Optional }
        );

@using eNtsaRegistrationTraining.Models
@model LoginViewModel
@{
    ViewBag.Title = "Login";
    Layout = "~/Views/Shared/_LoginLayout.cshtml";
}


<div class="login-box">
    <div class="login-logo">
        <a href="@Url.RouteUrl("Login")">eNtsa Registration</a>
    </div>
    <!-- /.login-logo -->
    <div class="card">
        <div class="card-body login-card-body">
            <p class="login-box-msg">Sign in to start your session</p>
            @using (Html.BeginForm("Index", "Account", new { ReturnUrl = ViewBag.ReturnUrl }, FormMethod.Post, new { @role = "form" }))
            {
                @Html.AntiForgeryToken()
                <div class="input-group mb-3">
                    @Html.TextBoxFor(m => m.Email, new { @class = "form-control", type = "email", placeholder = "Email", autofocus = "autofocus", required = "required" })
                    <div class="input-group-append">
                        <div class="input-group-text">
                            <span class="fas fa-envelope"></span>
                        </div>
                    </div>
                </div>
                <div class="input-group mb-3">
                    @Html.PasswordFor(m => m.Password, new { @class = "form-control", type = "password", placeholder = "Password" })
                    <div class="input-group-append">
                        <div class="input-group-text">
                            <span class="fas fa-lock"></span>
                        </div>
                    </div>
                </div>
                <div class="row">
                    <div class="col-8">
                        <div class="icheck-primary">
                            @Html.CheckBoxFor(m => m.RememberMe, new { @type = "checkbox", id = "remember" })
                            <label for="remember">
                                Remember Me
                            </label>
                        </div>
                    </div>
                    <!-- /.col -->
                    <div class="col-4">
                        <button type="submit" class="btn btn-primary btn-block">Sign In</button>
                    </div>
                    <!-- /.col -->
                </div>
            }

            <div class="social-auth-links text-center mb-3">
                <section id="socialLoginForm">
                    @*@Html.Partial("_ExternalLoginsListPartial", new ExternalLoginListViewModel { ReturnUrl = ViewBag.ReturnUrl })*@
                </section>
            </div>
            <!-- /.social-auth-links -->

            <p class="mb-1">
                <a href="@Url.RouteUrl("ForgotPasswd")">Forgot your password?</a>
            </p>
            <p class="mb-0">
                <a href="@Url.RouteUrl("Register")" class="text-center">Register a new membership</a>
            </p>
        </div>
        <!-- /.login-card-body -->
    </div>
</div>

<div class="modal fade" id="modal-danger" tabindex="-1" role="dialog" data-keyboard="false" data-backdrop="static">
    <div class="modal-dialog">
        <div class="modal-content bg-danger">
            <div class="modal-header">
                <h4 class="modal-title">Authentication Failed !</h4>
            </div>
            <div class="modal-body">
                @TempData["ErrorMessage"]
            </div>
            <div class="modal-footer justify-content-between">
                <button type="button" class="btn btn-outline-light" data-dismiss="modal">OK</button>
            </div>
        </div>
    </div>
</div>

<script type="text/javascript">
    function ShowErrorPopup() {
        $("#modal-danger").modal();
    }
</script>
@if (ViewBag.JavaScriptFunction != null)
{
    <script type="text/javascript">
            @Html.Raw(ViewBag.JavaScriptFunction)
    </script>
}