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: TPO991
name: 7/1990
tree-preservation-order: undefined
7/1990
tree-preservation-zone-type: group
geometry: MULTIPOLYGON (((0.653506 51.261204,0.653555 51.261208,0.653581 51.261230,0.653632 51.261293,0.653725 51.261382,0.653829 51.261499,0.653964 51.261671,0.654373 51.262037,0.654766 51.262339,0.654970 51.262466,0.655260 51.262615,0.655438 51.262719,0.655514 51.262772,0.655631 51.262872,0.655656 51.262903,0.655651 51.262932,0.655625 51.262958,0.655593 51.262974,0.655550 51.262976,0.655517 51.262967,0.655394 51.262873,0.655172 51.262737,0.654916 51.262600,0.654807 51.262551,0.654554 51.262401,0.654313 51.262217,0.654120 51.262050,0.653805 51.261749,0.653618 51.261530,0.653391 51.261283,0.653399 51.261240,0.653445 51.261214,0.653506 51.261204)))
point: POINT (0.65444 51.262124)
notes: The Maidstone Borough Council Tree Preservation Order No 7 of 1990 under Section 60 of the Town and Country Planning Act 1971 Group of Trees - G3 consisting of 14 Field Maple,
organisation
entry-date: 1990-10-05
start-date: 1990-10-02
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.