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: TPO06
name: 41/1981
tree-preservation-order: undefined
41/1981
tree-preservation-zone-type: group
geometry: MULTIPOLYGON (((0.570042 51.246801,0.569865 51.246816,0.569860 51.246835,0.569708 51.246865,0.569559 51.246880,0.569422 51.246865,0.569328 51.246792,0.569879 51.245452,0.570281 51.244530,0.570325 51.244500,0.570413 51.244494,0.570462 51.244516,0.570518 51.244522,0.570477 51.244642,0.570144 51.245400,0.569895 51.245999,0.569668 51.246455,0.569663 51.246493,0.569588 51.246709,0.569595 51.246756,0.569987 51.246709,0.570108 51.246713,0.570042 51.246801)))
point: POINT (0.569908 51.24576)
notes: The Maidstone Borough Council Tree Preservation Order No.41 of 1981 under the provisions of Section 60 of the Town and Country Planning Act 1971. Group of Trees - G1 comprising Lime (Tilia platyphylles),
organisation
entry-date: 1981-11-30
start-date: 1981-11-27
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.