Error in FI document create Message no. 8I031

Dear SAP GURUs,

While create Excise invoice by J1iin.System give error *Error in FI document create Message no. 8I031*.

Please help me out from this error .I have check all customization.

This error came when i assign a WBS in Sale order if i am not assign this wbs in sale order then their is no error generated.

With Regards

MK