Solution : https://service.sap.com/sap/support/notes/966645 (SAP Service marketplace login required)
Key words : 
getenvu16 rfc sdkenvironment command argv jlaunch tp reason, nlsui_alloc_wcsar encountered invalid utf-8    f9   characters previously read, environment conversion encountered invalid utf-8    c4 62, 0066 006f 006f                @ã·   --- unicode interface ------ end, unicode executables interpret command line parameters, //bas/640_rel/src/flat/nlsui1, //bas/700_rel/src/flat/nlsui1, product release patch sapexe 700 dw, 0066 006f 006f 003d 0076 0061 006c 0075, jlaunch tp executables built
Related Notes : 
       
| 1071731 | Unicode C-programs and access to OS environment | 
| 1048674 | core in Unicode UTF-8 environment scan | 
| 413708 | Current RFC library | 
| 11682 | Compiling RFC programs |