The following error message “Error: Cookies are blocked or not supported by your browser. You must enable cookies to use WordPress.” can be fixed with a few adjustments, usually quickly.
Solution: If the wp-config.php is error-free, the following additions can solve the problem.
define('WP_HOME','http://www.beispielseite.de');
define('WP_SITEURL','http://www.beispielseite.de');
define('COOKIE_DOMAIN','http://www.beispielseite.de');