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: TPO208
name: 21/1987
tree-preservation-order: undefined
21/1987
tree-preservation-zone-type: woodland
geometry: MULTIPOLYGON (((0.663209 51.272797,0.663483 51.273050,0.661132 51.274122,0.661028 51.274124,0.661367 51.273845,0.661576 51.273625,0.661621 51.273557,0.661911 51.273300,0.661947 51.273254,0.662101 51.273152,0.662133 51.273113,0.662194 51.273062,0.662307 51.272991,0.662363 51.272962,0.662597 51.272870,0.662623 51.272845,0.662654 51.272833,0.662606 51.272787,0.663006 51.272615,0.663209 51.272797)))
point: POINT (0.662406 51.273283)
notes: The Maidstone Borough Council Tree Preservation Order No 21 of 1987 under Section 60 of the Town and Country Planning Act 1971 Woodlands - W1 Mixed Deciduous trees consisting
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.