Solution : https://service.sap.com/sap/support/notes/484558 (SAP Service marketplace login required)
Key words : 
edit -> delete master data table lock, net change planning run, meta data error, conform internal values, gjahr conversion routines, master data, internal values, transaction data, messages appears, reactivate correct
Related Notes : 
       
| 545741 | Additional information on upgrading to BW 3.1 Content | 
| 447341 | values for ALPHA conversion routine |