Solution : https://service.sap.com/sap/support/notes/125637 (SAP Service marketplace login required)
Key words : 
additional key words component allocation, longer displays existing allocations, changing component allocations, module cs_ex_node_save althougha, phantom assemblytransactions ca01, update termination occurs, correction report zzstpf01, phantom assemblies, short dump, implemented   orb
Related Notes : 
       
| 82920 | Component allocation of phantom assemblies (BOM) | 
| 82644 | Component allocation of phantom assemblies (routing) |