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: TPO651
name: 9/1986
tree-preservation-order: undefined
9/1986
tree-preservation-zone-type: woodland
geometry: MULTIPOLYGON (((0.577777 51.274891,0.577708 51.275168,0.577739 51.275269,0.577193 51.275465,0.577118 51.275503,0.576745 51.275573,0.576517 51.275216,0.575760 51.275144,0.575719 51.275148,0.575483 51.275226,0.575403 51.275273,0.575214 51.275119,0.574806 51.274810,0.574557 51.274651,0.574500 51.274622,0.574358 51.274569,0.573851 51.274457,0.573873 51.274436,0.573909 51.274418,0.574867 51.273970,0.574861 51.273964,0.575073 51.273871,0.575268 51.273923,0.575332 51.273953,0.575388 51.274011,0.575407 51.274040,0.575407 51.274061,0.575525 51.274168,0.575650 51.274191,0.575680 51.274190,0.575855 51.274302,0.575956 51.274351,0.576205 51.274390,0.576268 51.274413,0.576727 51.274640,0.577193 51.274812,0.577236 51.274821,0.577293 51.274820,0.577422 51.274769,0.577483 51.274774,0.577549 51.274821,0.577567 51.274848,0.577568 51.274867,0.577602 51.274875,0.577684 51.274862,0.577728 51.274863,0.577765 51.274878,0.577777 51.274891)))
point: POINT (0.575894 51.274743)
notes: Maidstone Borough Council Tree Preservation Order No. 9 of 1986 under Section 60 of the Town and Country Planning Act 1971. Woodlands - W1 Comprising Sycamore, False Acacia, Cherry,
organisation
entry-date: 1986-09-19
start-date: 1986-09-12
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.