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: TPO956
name: 7/1990
tree-preservation-order: undefined
7/1990
tree-preservation-zone-type: group
geometry: MULTIPOLYGON (((0.659403 51.253675,0.659446 51.253679,0.659462 51.253691,0.659461 51.253712,0.659443 51.253737,0.659371 51.253771,0.658874 51.253950,0.658409 51.254128,0.658106 51.254254,0.657712 51.254434,0.657308 51.254633,0.656995 51.254799,0.656925 51.254806,0.656901 51.254795,0.656892 51.254769,0.656907 51.254748,0.656995 51.254688,0.657290 51.254534,0.658011 51.254187,0.658517 51.253982,0.658927 51.253827,0.659403 51.253675)))
point: POINT (0.658149 51.25421)
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 - G22 consisting of 54 Ash, 9 Beech,
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.