I have tried printing a DPD Local shipping label and am seeing an error returned:

Error: 1036: HS code is invalid (consignment.parcel.parcelProduct.productHarmonisedCode)


This error typically occurs if the HS code associated with an item is incorrect. You would need to check the Item's Extended Property value for the HS code and validate it on the appropriate website. 

For more detailed solution, follow the steps provided in the following article: Shipping - HS code is invalid