Change to Supplier Number is not allowed because F0411 records exist for this PO.

this is the error received when the buyer tries to change the supplier# from the header. the F4301 now has the supplier# as 3-C whereas all the lines on the PO detail line (F4311) has a supplier# 1-A and the F43121 and F43199 all the lines have the supplier# as 1-A. except the F0411 has partial lines with supplier# 2-B and the next set of partial lines witj supplier# 3-C where the last transactions from F4111 matches the F4301 hdr(3-C).

Now they would like to set the hdr back to 1-A since all the transactions in the PO points to 1-A except the F4111 and yes corresponding GL recs match the F0411 recs.