I have the following sumproduct formula that works on a subset of the target
range, but returns a #DIV/0! error for the full range below (i.e. it works
for rows 112 to 2122 & 3776 to 6730, does not work if rows 2123 to 3775 are
included).

=SUMPRODUCT(--('BS Details'!$D$112:$D$6730=$F$2),--('BS
Details'!$H$112:$H$6730=$A512),'BS Details'!I$112:I$6730)

The format of the data in the target range was brought in from another
workbook. Any ideas on what could be in the range of data that could be
causing this result?

Thanks,
DWhitney