Try to execute the sql on your database in some MySQL client like SQLyog or phpMyAdmin:
SELECT
trans.*
,ov_amount+ov_gst+ov_freight+ov_freight_tax+ov_discount AS Total
,cust.name AS DebtorName
, cust.address
, cust.curr_code
, cust.tax_id
, com.memo_
, shippers.shipper_name
, sales_types.sales_type
, sales_types.tax_included
, branch.*
, cust.discount
, tax_groups.name AS tax_group_name
, tax_groups.id AS tax_group_id
FROM debtor_trans trans
LEFT JOIN comments com ON trans.type=com.type AND trans.trans_no=com.id
LEFT JOIN shippers ON shippers.shipper_id=trans.ship_via
, debtors_master cust
, sales_types
, cust_branch branch
, tax_groups
WHERE trans.trans_no=''
AND trans.type='10'
AND trans.debtor_no=cust.debtor_no
AND sales_types.id = trans.tpe
AND branch.branch_code = trans.branch_code
AND branch.tax_group_id = tax_groups.id;and see what results you get.
Unless you used no Table Prefix, it seems to be missing here.
