in /root/ticket_browse.php on line 202 find

}

replace with this:

} elseif ($within_id == 'email')
{
$query_main .= "AND t.email LIKE '%{$search}%' ";
}


in /admin/ticket_browse.php on line 314 find

}

replace with this:

} elseif ($within_id == 'email')
{
$query_main .= "AND t.email LIKE '%{$search}%' ";
}