Cannot Zero the inventory Quantity using "count per inventory part" window.

@Thuzzith SM this error message suggests that you have reservations for this part no in location 01A. You would need to remove/cancel the reservation (customer order line / shop order material / transport task). You may go to Inventory Part In Stock Reservation screen and cancel the reserved qty.

Below is the piece of code that throws the error:

IF NVL(Inventory_Part_In_Stock_API.Get_Qty_Reserved(contract_ => newrec_.contract,                                                           
                                                    part_no_           => newrec_.part_no,
                                             configuration_id_  => newrec_.configuration_id,
                                                 location_no_       => newrec_.location_no,
                                                 lot_batch_no_      => newrec_.lot_batch_no,
                                                   serial_no_         => newrec_.serial_no,
                                                eng_chg_level_     => newrec_.eng_chg_level,
                                              waiv_dev_rej_no_   => newrec_.waiv_dev_rej_no,
                                                 activity_seq_      => newrec_.activity_seq,                             
            handling_unit_id_  => newrec_.handling_unit_id),0) > newrec_.qty_count1 THEN

  Error_SYS.Record_General('CountingReportLine', '753: Counted on-hand quantity :P1 for part :P2 is less than the allocations at location :P3.', newrec_.qty_count1, newrec_.part_no, newrec_.location_no);

END IF;