Solution : https://service.sap.com/sap/support/notes/86543 (SAP Service marketplace login required)
Key words : 
additional key words analysis program, symptom duplicate fi documents, display duplicate fi documents, check program, billing document, incorrectly implemented, mcv_statistics_invoice solution, prerequisites 1, note 74990, userexits 3
Related Notes : 
       
| 95614 | Correction program:missing FI documents f. invoices | 
| 95317 | Analysis: Billing docs available/accounting docs missing | 
| 84936 | Duplicated documents in accounting |