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: TPO186
name: 21/1987
tree-preservation-order: undefined
21/1987
tree-preservation-zone-type: woodland
geometry: MULTIPOLYGON (((0.671187 51.267367,0.671285 51.267474,0.671383 51.267653,0.671528 51.267994,0.671717 51.268349,0.671902 51.268755,0.672086 51.269096,0.672125 51.269190,0.672115 51.269276,0.672219 51.269637,0.672364 51.269921,0.672388 51.269952,0.672333 51.269967,0.672266 51.269999,0.672231 51.269937,0.672104 51.269759,0.672019 51.269586,0.671860 51.269303,0.671851 51.269169,0.671838 51.269103,0.671792 51.268975,0.671529 51.268540,0.671310 51.268127,0.671225 51.267992,0.671155 51.267914,0.671106 51.267792,0.671060 51.267622,0.671026 51.267587,0.670964 51.267494,0.670930 51.267367,0.671007 51.267344,0.671043 51.267343,0.671165 51.267351,0.671187 51.267367)))
point: POINT (0.671641 51.268524)
notes: The Maidstone Borough Council Tree Preservation Order No 21 of 1987 under Section 60 of the Town and Country Planning Act 1971 Woodlands - W2 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.