Changed Session handler to "Memory Cache" now can't login - Joomla! Forum - community, help and support

hi,
i'm having problem logging joomla site after having trouble performing site backup (it kept timing out) changed "session settings" in "session" tab of configuration.

specifically "session handler" changed , changed "memory cache". once clicked apply kicked out of session , tried log in, i've tried multiple user's credentials still won't login.

is there way manually change session handler database (if indeed problem). appreciated.

regards,
rob

change permissions of configuration.php 644 , edit configuration.php:

var $session_handler = 'database';