With relationships defined between tables, Power BI uses the following DAX query that fails with error
DEFINE
VAR __DS0Core =
SUMMARIZECOLUMNS(
ROLLUPADDISSUBTOTAL('product'[productnumber], "IsGrandTotalRowTotal"),
"Sumorderqty", CALCULATE(SUM('order_details'[orderqty]))
)
VAR __DS0PrimaryWindowed =
TOPN(502, __DS0Core, [IsGrandTotalRowTotal], 0, 'product'[productnumber], 1)
EVALUATE
__DS0PrimaryWindowed
ORDER BY
[IsGrandTotalRowTotal] DESC, 'product'[productnumber]