Solution : https://service.sap.com/sap/support/notes/408027 (SAP Service marketplace login required)
Key words : 
additional key words va01, update termination occurs, sales order item, sales order, assembly order, generated automatically, document links, abap processor, document integration, prerequisites note 391220
Related Notes : 
       
| 391220 | Document links in the collective order | 
| 381237 | Object links for production orders |