Tree preservation zone

There is a problem

1000 entries with tree-preservation-order field must match the reference field in the tree preservation order dataset

reference: TPO184
name: 21/1987
tree-preservation-order: undefined
21/1987
tree-preservation-zone-type: group
geometry: MULTIPOLYGON (((0.661914 51.269353,0.661977 51.269356,0.662039 51.269375,0.662100 51.269408,0.662191 51.269492,0.662268 51.269585,0.662440 51.269843,0.662553 51.270035,0.662567 51.270096,0.662546 51.270132,0.662506 51.270142,0.662404 51.270137,0.662307 51.270106,0.662216 51.270048,0.662106 51.269961,0.662049 51.269900,0.661834 51.269742,0.661705 51.269596,0.661666 51.269509,0.661673 51.269475,0.661696 51.269433,0.661778 51.269375,0.661914 51.269353)))
point: POINT (0.662113 51.269725)
notes: The Maidstone Borough Council Tree Preservation Order No 21 of 1987 under Section 60 of the Town and Country Planning Act 1971 Group of Trees - G5 comprising
organisation
entry-date: 1987-07-31
start-date: 1987-07-30
end-date

Your dataset is missing the tree-preservation-order column.

The Tree preservation zone guidance explains how to fix the issue:

The reference for the tree preservation order that covers this zone.