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: TPO169
name: 21/1987
tree-preservation-order: undefined
21/1987
tree-preservation-zone-type: group
geometry: MULTIPOLYGON (((0.685183 51.262265,0.685203 51.262301,0.685189 51.262346,0.685160 51.262375,0.685119 51.262392,0.685077 51.262392,0.685006 51.262350,0.684909 51.262235,0.684744 51.261907,0.684692 51.261848,0.684384 51.261624,0.684257 51.261503,0.684189 51.261413,0.684120 51.261346,0.684046 51.261239,0.684029 51.261185,0.684034 51.261151,0.684067 51.261124,0.684118 51.261118,0.684196 51.261147,0.684254 51.261211,0.684369 51.261380,0.684438 51.261462,0.684815 51.261781,0.684957 51.261964,0.685094 51.262177,0.685183 51.262265)))
point: POINT (0.684624 51.26175)
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 - G24 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.