This Bootstrap template requires a fix to the /includes/templates/bootstrap/common/tpl_offcanvas_menu.php file for 1.5.6 changes the table structure.

Around Line 152, find
PHP Code:
    $page_query $db->Execute("select * from " TABLE_EZPAGES " where status_sidebox = 1 and sidebox_sort_order > 0 order by sidebox_sort_order, pages_title"); 
change to
PHP Code:
// BOE - Bootstrap for 1.5.6     
    
$page_query $db->Execute("SELECT e.*, ec.*
                                FROM " 
TABLE_EZPAGES " e,
                                     " 
TABLE_EZPAGES_CONTENT " ec
                                WHERE e.pages_id = ec.pages_id
                                AND ec.languages_id = " 
. (int)$_SESSION['languages_id'] . "
                                AND e.status_sidebox = 1
                                AND e.sidebox_sort_order > 0
                                ORDER BY e.sidebox_sort_order, ec.pages_title"
);   
    
// old code for 1.5.5:
//    $page_query = $db->Execute("select * from " . TABLE_EZPAGES . " where status_sidebox = 1 and sidebox_sort_order > 0 order by sidebox_sort_order, pages_title");
// EOE - Bootstrap for 1.5.6