Tree preservation zone

There is a problem

reference: TPO 0006 (1966)/A23
name: BALSHAM Parish
tree-preservation-order: TPO 0006 (1966)
tree-preservation-zone-type: area
geometry: MULTIPOLYGON (((0.323319 52.134089,0.323321 52.134196,0.323297 52.134261,0.323303 52.134312,0.323417 52.134309,0.323943 52.136775,0.323970 52.136880,0.323982 52.136891,0.323765 52.137000,0.323016 52.137337,0.322874 52.137103,0.322844 52.136992,0.322790 52.136909,0.322587 52.136632,0.322373 52.136323,0.322341 52.136266,0.322118 52.136012,0.321953 52.135718,0.321904 52.135624,0.321772 52.135320,0.321654 52.135028,0.321606 52.134940,0.321501 52.134784,0.321345 52.134447,0.321137 52.134035,0.321127 52.133997,0.321126 52.133927,0.321141 52.133859,0.321253 52.133774,0.321447 52.133648,0.321612 52.133575,0.321605 52.133559,0.321624 52.133521,0.322149 52.133466,0.322288 52.133438,0.322938 52.133352,0.323027 52.133426,0.323023 52.133545,0.323050 52.133665,0.323042 52.133698,0.323036 52.133711,0.322852 52.133784,0.322736 52.133787,0.322691 52.133797,0.322677 52.133812,0.322697 52.133866,0.322692 52.133878,0.322672 52.133896,0.322631 52.133890,0.322663 52.134005,0.322750 52.134034,0.322827 52.134031,0.322837 52.134098,0.322874 52.134142,0.323319 52.134089),(0.322667 52.134197,0.322676 52.134194,0.322669 52.134194,0.322667 52.134197)))
point: POINT (0.322656 52.135186)
notes
entry-date: 2021-09-01
start-date: start-date must be a real date
1966-12-12
end-date

Your dataset is missing the start-date column.

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

The date that the tree preservation order came into force, written in YYYY-MM-DD format.

Example: 1984-03-28