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: ZZZZZRESRW908
name: Eton Rural District Council (Fulmer) Interim Preservation Order No.2; 1947; dated 31/12/47 affecting
tree-preservation-order: undefined
TPO/ER/1947/02
tree-preservation-zone-type
geometry: MULTIPOLYGON (((-0.554491 51.565521,-0.554555 51.565564,-0.554583 51.565578,-0.554609 51.565584,-0.554657 51.565589,-0.554682 51.565590,-0.554737 51.565588,-0.554758 51.565582,-0.554770 51.565576,-0.554799 51.565555,-0.554809 51.565546,-0.554823 51.565520,-0.554828 51.565480,-0.554819 51.565450,-0.554807 51.565430,-0.554794 51.565394,-0.554769 51.565372,-0.554734 51.565357,-0.554705 51.565351,-0.554678 51.565348,-0.554622 51.565353,-0.554602 51.565358,-0.554584 51.565368,-0.554564 51.565374,-0.554496 51.565388,-0.554479 51.565395,-0.554467 51.565403,-0.554455 51.565416,-0.554447 51.565428,-0.554445 51.565442,-0.554446 51.565461,-0.554452 51.565479,-0.554465 51.565498,-0.554491 51.565521)))
point: POINT (-0.554647 51.56547)
notes
entry-date: 2017-07-04
start-date: 2017-07-04
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.