title: Facebook login to site "An error occurred. Please try again later." happens only sometimes
body: <p>The website has moved from one domain name and server to another domain name and server. Facebook login doesn't work when I press fb login on the page, it says standard <strong>An error occurred. Please try again later.</strong>. </p>
  
  <p>I had such kind of problem earlier because App ID: or App Secret: were incorrect. Now that's not a problem, they are correct (doublechecked).</p>
  
  <pre><code>The settings in the fb account to be able to login from &lt;mydomain&gt;.com via fb are:
  Display Name:  Some name
  Namespace:  &lt;I left it empty&gt;
  Contact Email:  support@&lt;mydomain&gt;.com
  App Domains:   www.&lt;mydomain&gt;.com
  
  Hosting URL: You have not generated a URL through one of our partners (Get one)
  Sandbox Mode: Disabled
  
  Website with Facebook Login:
  Site URL:  http://www.&lt;mydomain&gt;.com
  </code></pre>
  
  <p>That's it. It doesn't work (if you were NOT logged in into fb account from the browser you're trying to use to login to my web site via fb)</p>
  
  <p>I've just switched to sandbox enabled and sandbox disabled back (probably, some settings need to be refreshed, I don't know).</p>
  
  <p>It still doesn't work.</p>
  
  <p>Tested on several browsers.</p>
  
  <p>Moreover, once I logged in into FB using my account and then signed out, it looks like it goes to the facebook page and suggests to login, everything looks fine. And it works even if I cleaned the cache and cookies in Chrome (the magic), once I logged in into fb.
  Does anyone know what is the problem and how to fix it?</p>
  
  <p>And of course, I used the real domain name instead of .</p>