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: ZZZZDVESXE757
name: The Urban District of Chesham Interim Preservation Order No 1 Approved by Minister of Town and Count
tree-preservation-order: undefined
TPO/1948/077
tree-preservation-zone-type
geometry: MULTIPOLYGON (((-0.591213 51.694803,-0.591142 51.694785,-0.590726 51.694660,-0.590705 51.694651,-0.590586 51.694609,-0.590368 51.694536,-0.590353 51.694564,-0.590345 51.694588,-0.590340 51.694623,-0.590339 51.694660,-0.590341 51.694678,-0.590353 51.694741,-0.590366 51.694793,-0.590382 51.694884,-0.590390 51.694917,-0.590393 51.694959,-0.590392 51.695032,-0.590398 51.695092,-0.590401 51.695117,-0.590413 51.695158,-0.590421 51.695178,-0.590439 51.695204,-0.590450 51.695214,-0.590462 51.695220,-0.590470 51.695226,-0.590491 51.695236,-0.590577 51.695272,-0.590696 51.695315,-0.590819 51.695353,-0.590876 51.695364,-0.591384 51.694854,-0.591213 51.694803)))
point: POINT (-0.590767 51.694955)
notes
entry-date: 2010-02-18
start-date: 2010-02-18
end-date

Your data is missing a tree-preservation-order.

The Tree preservation zone guidance explains how to fix the issue:

The reference for the tree preservation order that covers this zone.