Hi, we have also the same issue and the solution above proposed by cjhass resolved the problem. Could you add the fix to the next release of the plugin? I mention that we are using multisite istallation with domain mapping plugin and login by SSL secure connection, we don’t have any plugin modifying login page.
2015/12/26 19:38:21 [error] 5755#0: *368577 FastCGI sent in stderr: "/Sensors/LogInOut.php on line 101
PHP message: PHP Notice: Undefined index: log in /home/docroot/wp-content/plugins/wp-security-audit-log/classes/Sensors/LogInOut.php on line 101
