Solution : https://service.sap.com/sap/support/notes/797412 (SAP Service marketplace login required)
Key words :
planning object - guid, data type 'char', relevant support package, start transaction se16, business content version, 9aplobj key figure, business content, active version, kyfnm = '9aplobj', key figure
Related Notes :
| 568814 | Key figure /BI0/9AOIPLOBJ has the wrong data type |