Solution : https://service.sap.com/sap/support/notes/961245 (SAP Service marketplace login required)
Key words : 
system issues error message f5 735, attached correction instructions, program error, 'fi interface, small difference & & &, terms vf01, small difference, saplfaci reason, exchange rate, local currency
Related Notes : 
       
| 940827 | VF01/VF02: Error message F5 735 (Hungary) (2) | 
| 847204 | VF01/VF02: Error message F5 735 (Hungary) | 
| 731669 | AC interface: Exchange rate for tax line items (Hungary) |