I am getting the error message
Fatal error: Call to undefined function wp_validate_redirect() in /home/ringwood/public_html/wp-includes/functions.php on line 1305
after upgrading from 3.6 to 3.6.1. This has happened on a number of sites. I have been able to get around this by ftp-ing the 3.6 version of functions.php into the site, but this is not a good solution.
Any ideas? Or is this a known bug?