Solution : https://service.sap.com/sap/support/notes/334782 (SAP Service marketplace login required)
Key words : 
additional key words va02, sd sales order, configurable item, longer changeable, program error, solution implement, attached correction, correction, note 329927, prerequisites
Related Notes : 
       
| 418336 | Manually maintained components with configuration with set | 
| 365327 | Incorrect components in sales order for SET processing | 
| 329927 | Configuration - duplicated sub-items |