Solution : https://service.sap.com/sap/support/notes/517783 (SAP Service marketplace login required)
Key words : 
sap software center, highest priority correctly, access type 'a', lower priority, hierarchy access, hierarchy accesses, condition record, ipc generates, method _comparevarkeys, error message
Related Notes : 
       
| 500770 | Hierarchical accesses may cause NullPointerExceptions | 
| 492015 | IPC: Internal error during hierarchy access | 
| 486061 | How to get patches for CRM Internet Pricing Configurator |