Solution : https://service.sap.com/sap/support/notes/118119 (SAP Service marketplace login required)
Key words : 
periodic billing plan incomplete settlement periods result, additional key words billing plan, shortened settlement period, diagnosisthe settlement period, billing plan, message class v2, validity period, fpla-endat, fpla-tndat, rv60f-abrbe
Related Notes : 
       
| 183784 | Incorrect settlement period in the billing plan | 
| 135634 |