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: TPO839
name: 15/1986
tree-preservation-order: undefined
15/1986
tree-preservation-zone-type: area
geometry: MULTIPOLYGON (((0.670930 51.267367,0.671007 51.267344,0.671165 51.267351,0.671262 51.267444,0.671296 51.267491,0.671383 51.267653,0.671528 51.267994,0.671590 51.268121,0.671717 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)))
point: POINT (0.671641 51.268525)
notes: Maidstone Borough Council Tree Preservation Order No 15, 1986 under Section 60 of the Town and Country Planning Act 1971 dated 18th July 1986. Confirmed 8th October 1986
organisation
entry-date: 1986-08-13
start-date: 1986-10-08
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.