Received the following error when i Network activated Post Voting

hiya, received the following error when i Network activated Post Voting, something to do w/ header and Commons in a box. ty

Warning: call_user_func() expects parameter 1 to be a valid callback, cannot access protected method Plugin_Dependencies::deactivate_conflicting() in /home/mtbmtbco/public_html/wp-content/plugins/commons-in-a-box/lib/wp-plugin-dependencies/plugin-dependencies.php on line 509

Warning: Cannot modify header information - headers already sent by (output started at /home/mtbmtbco/public_html/wp-content/plugins/commons-in-a-box/lib/wp-plugin-dependencies/plugin-dependencies.php:509) in /home/mtbmtbco/public_html/wp-includes/pluggable.php on line 899

Warning: Cannot modify header information - headers already sent by (output started at /home/mtbmtbco/public_html/wp-content/plugins/commons-in-a-box/lib/wp-plugin-dependencies/plugin-dependencies.php:509) in /home/mtbmtbco/public_html/wp-includes/pluggable.php on line 899