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: TPO474
name: 20/1987
tree-preservation-order: undefined
20/1987
tree-preservation-zone-type: group
geometry: MULTIPOLYGON (((0.659160 51.276617,0.659220 51.276600,0.659294 51.276602,0.659361 51.276642,0.659366 51.276678,0.659321 51.276730,0.658896 51.277055,0.658798 51.277190,0.658578 51.277378,0.658367 51.277573,0.658263 51.277696,0.658168 51.277787,0.658095 51.277880,0.658079 51.277991,0.657969 51.278295,0.657952 51.278449,0.657847 51.278605,0.657753 51.278774,0.657602 51.278929,0.657604 51.278979,0.657508 51.278973,0.657418 51.278943,0.657627 51.278584,0.657737 51.278315,0.657770 51.278177,0.657861 51.277904,0.657886 51.277854,0.657981 51.277711,0.658088 51.277595,0.658407 51.277299,0.658641 51.277042,0.658720 51.276967,0.659087 51.276663,0.659160 51.276617)))
point: POINT (0.658268 51.277728)
notes: The Maidstone Borough Council Tree Preservation Order No 20 of 1987 under Section 60 of the Town and Country Planning Act 1971 Group of Trees - G29 comprising of 8 Pine, 9 Beech,
organisation
entry-date: 1987-07-14
start-date: 1987-07-09
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.