EDI 856 Error

[jrdbrp]

Any ideas on what the follow error means on an 856 transmission?

Message(s): Loop-HL[Segment-HL/Element-735='O'][2]/Segment-PRF/Element-324 found Missing order number

I've looked through the records and can see the order number, still not sure what the error is. Any help would be appreciated.

 

[ImEDIabhishek]

From what im aware of, HL segment errors mainly come for Quantity error, for same Item, Quantity will split. Another is Carton repeat.

PRF segment is for PO number Normally,