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: TPO909
name: 3/1980
tree-preservation-order: undefined
3/1980
tree-preservation-zone-type: woodland
geometry: MULTIPOLYGON (((0.714835 51.253766,0.714763 51.253791,0.714724 51.253790,0.714673 51.253779,0.714597 51.253748,0.714372 51.253577,0.714336 51.253528,0.714160 51.253374,0.714115 51.253307,0.713914 51.253090,0.713637 51.252838,0.713286 51.252401,0.713184 51.252285,0.713024 51.252017,0.712960 51.251884,0.712922 51.251771,0.712902 51.251689,0.712899 51.251624,0.712910 51.251421,0.712908 51.251209,0.712829 51.250913,0.712780 51.250788,0.712876 51.250807,0.712988 51.251155,0.712993 51.251204,0.712977 51.251613,0.713108 51.251988,0.713230 51.252146,0.713343 51.252309,0.713749 51.252798,0.714338 51.253346,0.714431 51.253456,0.714537 51.253556,0.714653 51.253645,0.714674 51.253668,0.714697 51.253716,0.714766 51.253758,0.714835 51.253766)))
point: POINT (0.713613 51.252522)
notes: The Maidstone Borough Council Tree Preservation Order No 3 of 1980 under Section 60 of the Town and Country Planning Act 1971 Woodlands - W1 Hedgerow belt 10 metres wide from
organisation
entry-date: 1980-01-04
start-date: 1980-01-04
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.