title: Wordpress admin login cookies blocked error after moving servers
body: <p>Background: had a working Wordpress 3.7 site at olddomain.com.</p>
  
  <p>I moved it to newdomain.com successfully, and in the process added this to wp-config:</p>
  
  <pre><code>define('WP_HOME','http://newdomain.com');
  define('WP_SITEURL','http://newdomain.com');
  </code></pre>
  
  <p>Now when I attempt to login from newdomain.com/wp-admin I'm getting the cross-browser error (despite having cookies enabled and clearing existing cookies):</p>
  
  <pre><code>ERROR: Cookies are blocked or not supported by // your browser. 
  You must enable cookies to use WordPress.
  </code></pre>
  
  <p>I tried going into wp-login.php and commenting out the following lines (744-747) to stop the conditional testcookie check</p>
  
  <pre><code>    // If cookies are disabled we can't log in even with a valid user+pass
  if ( isset($_POST['testcookie']) &amp;&amp; empty($_COOKIE[TEST_COOKIE]) )
      $user = new WP_Error('test_cookie', __("&lt;strong&gt;ERROR&lt;/strong&gt;: Cookies are blocked or not supported by // your browser. You must &lt;a href='http://www.google.com/cookies.html'&gt;enable cookies&lt;/a&gt; to use WordPress."));
  else
      $user = wp_signon('', $secure_cookie);
  </code></pre>
  
  <p>but doing that leaves me stuck in a redirect loop back to the admin page:</p>
  
  <pre><code>http://myapp.com/wp-login.php?redirect_to=http%3A%2F%2Fmyapp.com%2Fwp-admin%2F&amp;reauth=1
  </code></pre>
  
  <p>Do I need to change (or not set) the site URL? or is there another potential way to troubleshoot this? thanks </p>