title: How can I fix anti-forgery token was meant for user "", but the current user is "xxxx " error
body: <p>The provided anti-forgery token was meant for user "", but the current user is "xxxx   ".</p>
  
  <p>I have followed every single solution possible to get rid of this error without any success:</p>
  
  <p>Here is the scenario:
  I have 2 separate log in tabs open in my browser tab A Tab B: 
  1.  I login to my site in Tab A
  2.  Then try to log in Tab B</p>
  
  <p>The above error then occurs</p>
  
  <p>My C# web MVC login view has:</p>
  
  <pre><code>v class="col-md-4 col-md-offset-4"&gt;
                  &lt;form class="form-signin" role="form" action=@Url.Action("Login", "Account") method="POST" id="signInForm"&gt;
                       @Html.AntiForgeryToken()
                      &lt;div class="form-group"&gt;
                          &lt;label for="loginEmail"&gt;Email&lt;/label&gt;
                          &lt;input  type="text" id="loginEmail" name="loginEmail" class="form-control" placeholder="Email address" &gt;
                      &lt;/div&gt;
                      &lt;div class="form-group"&gt;
                          &lt;label for="loginPassword"&gt;Password&lt;/label&gt;
                          &lt;input id="loginPassword" type="password"  name="loginPassword" class="form-control" placeholder="Password" &gt;
                      &lt;/div&gt;
                      &lt;button class="btn btn-lg btn-primary btn-block main-btn" type="submit"&gt;Sign in&lt;/button&gt;
                      &lt;div&gt;
                          &lt;br&gt;
                          &lt;a href="@Url.Action("Index","GettingStarted")"&gt;Register&lt;/a&gt;&lt;br&gt;
                          &lt;a href="@Url.Action("ForgotPassword","Account")"&gt;Forgot your password?&lt;/a&gt;
                      &lt;/div&gt;
                  &lt;/form&gt;
  </code></pre>
  
  <p>And my accounts controller like this:</p>
  
  <pre><code>[HttpPost]
  [AllowAnonymous]
  [ValidateAntiForgeryToken]
  public ActionResult Login(LoginModel model)
  {
  
      if (ModelState.IsValid)
      {
  </code></pre>
  
  <p>How can I fix this error?</p>