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: TPO777
name: 8/1971
tree-preservation-order: undefined
8/1971
tree-preservation-zone-type: woodland
geometry: MULTIPOLYGON (((0.600091 51.325429,0.599467 51.324816,0.599058 51.324401,0.598109 51.323577,0.598090 51.323557,0.598044 51.323475,0.598048 51.323454,0.598750 51.323066,0.599036 51.322955,0.599276 51.323072,0.599748 51.323216,0.599806 51.323246,0.599969 51.323369,0.599975 51.323385,0.599956 51.323431,0.599958 51.323469,0.599968 51.323488,0.600122 51.323633,0.600145 51.323660,0.600182 51.323742,0.600201 51.323765,0.601154 51.324875,0.603009 51.324159,0.603369 51.324504,0.603008 51.324652,0.602769 51.324780,0.600091 51.325429)))
point: POINT (0.600177 51.324265)
notes: County of Kent (Hollingbourne Rural District) Tree Preservation Order No 8 of 1971 confirmed 23th November, 19 Woodlands - W1 Oak, Beech and Ash standards over Sweet Chestnut, Ash and Hornbeam
organisation
entry-date: 1971-07-09
start-date: 1971-06-25
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.