Takayuki Miyoshi on "[Plugin: Contact Form 7] location.replace not working with WPCF7_LOAD_JS', false"

Remove define ('WPCF7_LOAD_JS', false); line from wp-config.php, check what is causing the endless spinning arrow issue by deactivating all other plugins and switching to the default theme as FAQ says, don't modify any files in WordPress or plugins and restore files if you have modified them. If you still see the issue, check the PHP error logs on your server.