Solution : https://service.sap.com/sap/support/notes/1082002 (SAP Service marketplace login required)
Key words : 
goods issue posting, goods receipt posting, extended warehouse management, unique number assignment, error message huselect 008, error occurs, outbound delivery, handling unit, inbound delivery, confirmation message
Related Notes : 
       
| 1171263 | Goods issue posting fails with message HUSELECT 008 | 
| 1075464 | HUDIALOG 400 when packing batch in several handling units |