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: TPO820
name: 1/1993
tree-preservation-order: undefined
1/1993
tree-preservation-zone-type: woodland
geometry: MULTIPOLYGON (((0.468980 51.270193,0.469301 51.270235,0.469194 51.270313,0.469109 51.270460,0.469104 51.270540,0.469128 51.270884,0.469152 51.271026,0.469147 51.271065,0.469121 51.271116,0.469074 51.271176,0.469030 51.271214,0.468983 51.271235,0.468839 51.271261,0.467439 51.271275,0.467176 51.271301,0.467131 51.271310,0.467137 51.271332,0.467078 51.271317,0.466388 51.271316,0.465105 51.271370,0.464990 51.269750,0.465016 51.269561,0.465002 51.269325,0.465834 51.269418,0.466074 51.269422,0.466106 51.269686,0.466249 51.270188,0.467244 51.270135,0.467441 51.270116,0.467442 51.270137,0.467782 51.270110,0.468140 51.270106,0.468401 51.270116,0.468980 51.270193)))
point: POINT (0.466829 51.270573)
notes: The Maidstone Borough Council Tree Preservation Order No 1 of 1993 under Section 198 of the Town and Country Planning Act 1990 Woodlands - W1 Consisting mainly Hornbeam,
organisation
entry-date: 1993-02-06
start-date: 1993-02-05
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.