Solution : https://service.sap.com/sap/support/notes/608143 (SAP Service marketplace login required)
Key words : 
runtime error occurs, source code correction, external program reason, nls_get_langu_cp_tab function module, sap unicode system, function module, external system, -sap destination, send idocs, terms idoc
Related Notes : 
       
| 613389 | ALE SAP system group with Unicode systems |