`{stat}` on `{col}` cannot be computed over ...

Warnings reference › stat.pivot-unsupported:reduce:*:*

Identifier

stat.pivot-unsupported:reduce:*:*

Raised by

The grid (core)

Since

1.79.0

What happened

A pivot's terminal groups are pushed down and answered as aggregated cells: they carry no leaf rows at all, so reduce() would otherwise read the pivot's own aggregated group rows as if they were the leaf population a reduction describes - a wrong number with no symptom. reduce() returns null instead, and this fires once per statistic and column.

The fix

Turn the pivot off to reduce the leaf population, or read the number the grid already computed from the pivot's own cells (grid.rows.value) instead of reduce().

Reference

Covered in full at the API reference.