Solution : https://service.sap.com/sap/support/notes/1092070 (SAP Service marketplace login required)
Key words : 
runtime error         convt_codepageexception             cx_sy_conversion_codepage, import account statement files, account statement reason, attached advance corrections, find detailed information, system code page, user parameter ucp, unicode code page, solution import, parameter ucp
Related Notes : 
       
| 758870 | Account statement: Character set when the file is uploaded |