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: TPO661
name: 16/1986
tree-preservation-order: undefined
16/1986
tree-preservation-zone-type: group
geometry: MULTIPOLYGON (((0.657301 51.279163,0.657313 51.279140,0.657397 51.279151,0.657510 51.279185,0.657501 51.279217,0.657472 51.279256,0.657437 51.279333,0.657389 51.279399,0.657360 51.279483,0.657289 51.279640,0.657163 51.279893,0.657112 51.279906,0.657059 51.279894,0.657008 51.279874,0.657182 51.279422,0.657301 51.279163)))
point: POINT (0.65725 51.279509)
notes: Maidstone Borough Council Tree Preservation Order No 16 of 1986 under Section 60 of the Town and Country Planning Act 1971 Group of Trees - G11 comprising 3 Pine, 9 Field
organisation
entry-date: 1986-08-13
start-date: 1986-07-19
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.