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: TPO267
name: 20/1987
tree-preservation-order: undefined
20/1987
tree-preservation-zone-type: group
geometry: MULTIPOLYGON (((0.661901 51.287410,0.661962 51.287409,0.662008 51.287427,0.662024 51.287458,0.662017 51.287492,0.661644 51.287617,0.660956 51.287863,0.660829 51.287919,0.660649 51.287958,0.660529 51.287994,0.660512 51.288015,0.660490 51.288025,0.660270 51.288088,0.659822 51.288242,0.659449 51.288339,0.659265 51.288420,0.659044 51.288472,0.658912 51.288517,0.658793 51.288524,0.658749 51.288494,0.658742 51.288457,0.658890 51.288328,0.658986 51.288269,0.659137 51.288221,0.659271 51.288201,0.659712 51.288091,0.660507 51.287858,0.660803 51.287759,0.661067 51.287652,0.661364 51.287567,0.661682 51.287458,0.661901 51.287410)))
point: POINT (0.660271 51.287995)
notes: The Maidstone Borough Council Tree Preservation Order No 20 of 1987 under Section 60 of the Town and Country Planning Act 1971 Group of Trees - G26 comprising 2 Ash, 63 Poplars
organisation
entry-date: 1987-07-14
start-date: 1987-07-09
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.