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: TPO135
name: 4/1980
tree-preservation-order: undefined
4/1980
tree-preservation-zone-type: group
geometry: MULTIPOLYGON (((0.685078 51.247754,0.685255 51.247745,0.685392 51.247726,0.686105 51.247587,0.686163 51.247724,0.686266 51.247900,0.686472 51.248207,0.686466 51.248236,0.686412 51.248316,0.686370 51.248421,0.686289 51.248572,0.686297 51.248591,0.686858 51.249262,0.686766 51.249267,0.686590 51.249261,0.686453 51.249278,0.686418 51.249255,0.686379 51.249200,0.686139 51.248959,0.685969 51.248762,0.685820 51.248620,0.685589 51.248351,0.685404 51.248118,0.685284 51.248001,0.685173 51.247907,0.685082 51.247793,0.685078 51.247754)))
point: POINT (0.685992 51.24831)
notes: The Maidstone Borough Council Tree Preservation Order No 4 of 1980 under Section 60 of the Town and Country Planning Act 1971 Group of Trees - G4 comprising 37 individual
organisation
entry-date: 1980-02-19
start-date: 1980-02-15
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.