Can't attach group to node...

I get the following error:

PDOException: SQLSTATE[HY000]: General error: 1366 Incorrect integer value: '' for column 'sa_update' at row 1: INSERT INTO {simple_access_node} (nid, gid, sa_view, sa_update, sa_delete) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4); Array ( [:db_insert_placeholder_0] => 17 [:db_insert_placeholder_1] => 1 [:db_insert_placeholder_2] => 1 [:db_insert_placeholder_3] => [:db_insert_placeholder_4] => ) in simple_access_node_save() (line 254 of /var/www/vhosts/winhoodhomes.com/httpdocs/drupal/sites/all/modules/simple_access/simple_access.module).