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: ZZZZDTESXE980
name: The Chiltern District Council (Land at Lower Road, Chalfont St Peter) Tree Preservation Order 1994 N
tree-preservation-order: undefined
TPO/1994/015
tree-preservation-zone-type
geometry: MULTIPOLYGON (((-0.549977 51.597506,-0.549991 51.597513,-0.550023 51.597549,-0.550038 51.597599,-0.550060 51.597641,-0.550277 51.598030,-0.550313 51.598097,-0.550476 51.598365,-0.551185 51.598332,-0.551112 51.598219,-0.551065 51.598171,-0.550999 51.598089,-0.550955 51.598023,-0.550945 51.598004,-0.550939 51.597988,-0.550932 51.597956,-0.550814 51.597781,-0.550729 51.597651,-0.550642 51.597499,-0.550571 51.597365,-0.550457 51.597163,-0.550446 51.597142,-0.550436 51.597117,-0.550407 51.597037,-0.550315 51.596768,-0.550271 51.596629,-0.550251 51.596572,-0.550195 51.596394,-0.550139 51.596186,-0.550129 51.596141,-0.550087 51.595985,-0.550049 51.595828,-0.549997 51.595587,-0.549978 51.595509,-0.549927 51.595269,-0.549902 51.595163,-0.549883 51.595068,-0.549790 51.594665,-0.548343 51.594819,-0.548389 51.594886,-0.548455 51.594989,-0.548493 51.595044,-0.548512 51.595077,-0.548708 51.595372,-0.548848 51.595587,-0.548864 51.595617,-0.549017 51.595863,-0.549089 51.595983,-0.549151 51.596090,-0.549206 51.596180,-0.549310 51.596359,-0.549346 51.596417,-0.549421 51.596545,-0.549441 51.596575,-0.549854 51.597276,-0.549977 51.597506)))
point: POINT (-0.549749 51.596267)
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.