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: ZZZZZSESRW400
name: The Eton Rural District Tree Preservation Order No.2; 1964; dated 12/11/64; made under S.29 of the T
tree-preservation-order: undefined
TPO/BD/1964/02
tree-preservation-zone-type
geometry: MULTIPOLYGON (((-0.599828 51.563092,-0.599069 51.563007,-0.599052 51.563063,-0.599147 51.563075,-0.599140 51.563434,-0.599126 51.563504,-0.600125 51.563610,-0.600259 51.563141,-0.599828 51.563092)),((-0.599828 51.563092,-0.599948 51.562511,-0.599634 51.562427,-0.599628 51.562435,-0.599391 51.562506,-0.599234 51.562625,-0.599149 51.562722,-0.599105 51.562790,-0.599066 51.562882,-0.599047 51.562969,-0.599043 51.563004,-0.599828 51.563092)),((-0.602188 51.561815,-0.602431 51.561652,-0.602159 51.561457,-0.601948 51.561561,-0.601852 51.561554,-0.601513 51.561644,-0.601584 51.561747,-0.601204 51.561870,-0.601556 51.562198,-0.601704 51.562126,-0.601921 51.562005,-0.602188 51.561815)))
point: POINT (-0.60028 51.562684)
notes
organisation
entry-date: 2017-07-04
start-date: 2017-07-04
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.