Can't get into admin page

Everytime I go to my admin page I get the below error. Anyone know how to fix this?

Warning: call_user_func_array() expects parameter 1 to be a valid callback, function ‘woocommerce_sidebar_login_process’ not found or invalid function name in /home/ekkama/kawaiikigu.ca/wp-includes/plugin.php on line 406

Warning: session_start() [function.session-start]: Cannot send session cookie – headers already sent by (output started at /home/ekkama/kawaiikigu.ca/wp-includes/plugin.php:406) in /home/ekkama/kawaiikigu.ca/wp-includes/plugin.php on line 406

Warning: session_start() [function.session-start]: Cannot send session cache limiter – headers already sent (output started at /home/ekkama/kawaiikigu.ca/wp-includes/plugin.php:406) in /home/ekkama/kawaiikigu.ca/wp-includes/plugin.php on line 406

Warning: Cannot modify header information – headers already sent by (output started at /home/ekkama/kawaiikigu.ca/wp-includes/plugin.php:406) in /home/ekkama/kawaiikigu.ca/wp-includes/pluggable.php on line 876