The grid (core) · console.warn

grouping is active on a grid configured with...

Printed by The grid (core), prefixed [lattice], since 1.4.0.

Warnings reference › tree.grouped

Identifier: tree.grouped
Raised by: The grid (core)
Since: 1.4.0

What happened

A tree and a grouping are two different hierarchies over the same rows and only one can be drawn. The grouping wins, so the tree structure is not shown until the grouping is cleared.

The fix

Clear the grouping (grid.columns.group([])) to see the tree again, or accept the grouping.

Reference

Covered in full at the API reference.