two rows share a tree.path; the later ones were nested beneath the first.

Warnings reference › tree.path.duplicate

Identifier

tree.path.duplicate

Raised by

The grid (core)

Since

1.0.1

What happened

Two data rows resolve to the same path, and a path identifies one node. The second and later rows become children of the first, which is the only reading that loses no data - but it invents a level of hierarchy that is not in your data.

The fix

Make each row's path unique, usually by appending the row's own id as the last segment.

Reference

Covered in full at the API reference.