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: TPO351
name: 6/1983
tree-preservation-order: undefined
6/1983
tree-preservation-zone-type: group
geometry: MULTIPOLYGON (((0.613644 51.274080,0.613616 51.274055,0.613633 51.274027,0.613726 51.274001,0.613755 51.273985,0.613822 51.273972,0.613912 51.273966,0.614176 51.273983,0.614332 51.273952,0.614442 51.273911,0.614595 51.273910,0.614987 51.273865,0.615154 51.273871,0.615370 51.273927,0.615491 51.273946,0.615511 51.273959,0.615511 51.273978,0.615487 51.274009,0.615374 51.274038,0.615262 51.274053,0.614889 51.274036,0.614621 51.274042,0.614369 51.274061,0.614103 51.274110,0.613826 51.274109,0.613644 51.274080)))
point: POINT (0.614602 51.273992)
notes: Maidstone Borough Council Tree Preservation Order No 6 of 1983 under Section 60 of the Town and Country Planning Act 1971 Group of Trees - G3 comprising 27 Oak
organisation
entry-date: 1999-09-30
start-date: 1983-02-24
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.