Error uploading Bin Transfer: "You do not have permissions to set a value for element inventory

I am encountering the following error while attempting to upload a new Bin Transfer record to NetSuite: "You do not have permissions to set a value for element inventoryassignment.receiptinventorynumber due to one of the following reasons: 1) The field is read-only; 2) An associated feature is disabled; 3) The field is available either when a record is created or updated, but not in both cases."

 // create new Bin Transfer  BinTransfer newBT = new BinTransfer();  newBT.location = new RecordRef { internalId = "43" };    // create new Bin Transfer Inventory record  BinTransferInventory newBTInventory = new BinTransferInventory();  newBTInventory.item = new RecordRef { internalId = "42810" };  newBTInventory.quantity = 1;  newBTInventory.quantitySpecified = true;    // fill Inventory Assignment  InventoryAssignment BTInventoryAssignment = new InventoryAssignment();  <span style="color:'#FF0000'"><strong>BTInventoryAssignment.receiptInventoryNumber = "H0X1234";</strong></span>  BTInventoryAssignment.binNumber = new RecordRef { internalId = "15" };  BTInventoryAssignment.toBinNumber = new RecordRef { internalId = "16" };  BTInventoryAssignment.quantity = 1;  BTInventoryAssignment.quantitySpecified = true;    // add Inventory Assignment to Inventory Record  newBTInventory.inventoryDetail = new InventoryDetail();  newBTInventory.inventoryDetail.inventoryAssignmentList = new InventoryAssignmentList();  newBTInventory.inventoryDetail.inventoryAssignmentList.inventoryAssignment