title: magento from linux to windows cannot login - invalid formkey
body: <p>I transferred my magento installation on ubuntu with files and mysql db dump to my development machine on Windows 10 with XAMPP installed.</p>
  
  <p>I can up the frontend, but I cannot login my admin backend.</p>
  
  <p>I am sure the password and user name are exactly as my installation on ubuntu, why happened? It just stay on the login form and saying all the time invalid formkey, I viewed the source formkey value just generated there.</p>
  
  <p>There mentioned issue with charset, tried no help.</p>
  
  <p>There is no any error logged in var/report and XAMPP apache errorlog, access_log to /index.php/admin is 200, looks good.</p>
  
  <p>will you have any idea? thanks in advance.</p>