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: ZZZZDVESXE761
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 (((-0.604121 51.703079,-0.604146 51.703143,-0.604152 51.703149,-0.604155 51.703150,-0.604189 51.703156,-0.604303 51.703134,-0.604356 51.703127,-0.604372 51.703115,-0.604404 51.703104,-0.604533 51.703009,-0.604743 51.702877,-0.604776 51.702843,-0.604784 51.702832,-0.604786 51.702817,-0.604786 51.702800,-0.604784 51.702778,-0.604769 51.702677,-0.604816 51.702566,-0.604820 51.702477,-0.604775 51.702460,-0.604756 51.702458,-0.604707 51.702467,-0.604680 51.702481,-0.604662 51.702493,-0.604536 51.702608,-0.604169 51.702955,-0.604147 51.702981,-0.604123 51.703016,-0.604119 51.703028,-0.604116 51.703049,-0.604117 51.703064,-0.604121 51.703079)))
point: POINT (-0.604499 51.702835)
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.