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: TPO508
name: 20/1987
tree-preservation-order: undefined
20/1987
tree-preservation-zone-type: woodland
geometry: MULTIPOLYGON (((0.675408 51.279760,0.675270 51.279932,0.674803 51.280390,0.673717 51.280074,0.673809 51.279938,0.673523 51.279705,0.673338 51.279393,0.673547 51.279129,0.674014 51.278488,0.674232 51.278429,0.674310 51.278445,0.674736 51.278698,0.674746 51.278692,0.674894 51.278817,0.674935 51.278904,0.674956 51.279115,0.674984 51.279215,0.675062 51.279339,0.675345 51.279670,0.675408 51.279760)))
point: POINT (0.674364 51.279451)
notes: The Maidstone Borough Council Tree Preservation Order No 20 of 1987 under Section 60 of the Town and Country Planning Act 1971 Woodlands - W5 Mixed Deciduous trees consisting
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.