Error on Copying PO lines into Voucher

Hello,

We are on PeopleSoft 9.2 Image #33. User is trying to create a voucher by copying it from a PO ( Copy from PO Only). Business Unit & PO Number information is populated, and then Search button is clicked--lines are displayed for selection. Once the lines are selected, user clicks on "Copy Selected lines" and gets the below error----

Error-

SetID not found for name='BUSINESS_UNIT', value='' with record 'GL_ACCOUNT_TBL', tree ''. (2,214) VCHR_PANELS_WRK.VCHR_TEMPLATE_ID.FieldChange Name:stat_dsply_atCopy PCPC:415 Statement:6

Called from:FUNCLIB_APINTFC.VCHR_COPY_HDR.FieldFormula Name:Copy_MTCH_WS2_To_Distrib_Line Statement:2329