Hi Jurgen,
As you have suggested i have removed the account assignment objects and now i am not getting the error as mentioned in my post but at the same time i notice in export parameters in the bapi the following things which was not present earlier.
GOODSMVT_HEADRET 50000xxxxx2014
MATERIALDOCUMENT 50000xxxxx
MATDOCUMENTYEAR 2014
Now another thing is i am not getting any entry in return table.... which i should get. Please note that my test run contains no values(X).
i think i am near to the solution. Could you suggest any more crucial points i might be missing?