Solution : https://service.sap.com/sap/support/notes/43723 (SAP Service marketplace login required)
Key words : 
create/change capital investment program positions, additional key words eap019, prerequisites program error, unjustified error message, initial screen, advance correction, pay attention, release level
Related Notes : 
       
| 48103 | IM: Error AP130/AP131 when deleting edit screen | 
| 48064 | Cap.invstmt progs:edit screen cannot be deleted | 
| 40357 | CIP: Error AP024 when creating edit mask | 
| 39321 | Capital inv. prog.: Runtime error or EAP019/20/21/22 | 
| 39311 | IM: Runtime error when maintaining edit screens | 
| 26393 | IM: Maintaining coding masks not possible OR ... |