Solution : https://service.sap.com/sap/support/notes/182435 (SAP Service marketplace login required)
Key words : 
additional key words cu51, setting planned/prod, order bom setting, solution implement notes 146309, arrow keys, profile settings, program error, advance corrections, assignment screen, assignment
Related Notes : 
       
| 150112 | 3.1I+: Lower-level configuration not displayed | 
| 146309 | 3.1+:Values can't be assigned to subord. instances |