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: TPO26
name: 10/1996
tree-preservation-order: undefined
10/1996
tree-preservation-zone-type: group
geometry: MULTIPOLYGON (((0.623526 51.231969,0.623464 51.231789,0.623218 51.231293,0.622770 51.230422,0.621875 51.228645,0.620864 51.226680,0.621234 51.226629,0.621662 51.226584,0.622121 51.226566,0.622338 51.226574,0.622695 51.226568,0.623407 51.226513,0.623594 51.226505,0.623829 51.226532,0.624805 51.226761,0.624984 51.226813,0.624944 51.226871,0.624886 51.226992,0.624823 51.227197,0.624790 51.227356,0.624751 51.227448,0.624651 51.227597,0.624550 51.227698,0.624510 51.227771,0.624488 51.227843,0.624412 51.228004,0.624248 51.228255,0.624238 51.228310,0.624237 51.228385,0.624270 51.228513,0.624317 51.228624,0.624343 51.228741,0.624332 51.228871,0.624252 51.229248,0.624205 51.229403,0.624117 51.229606,0.624072 51.229684,0.623845 51.229928,0.623797 51.230012,0.623789 51.230058,0.623816 51.230131,0.623965 51.230329,0.624030 51.230428,0.624154 51.230682,0.624187 51.230729,0.624620 51.231128,0.624731 51.231204,0.624717 51.231243,0.624827 51.231372,0.624622 51.231428,0.624401 51.231523,0.623759 51.231892,0.623555 51.232001,0.623530 51.231984,0.623526 51.231969)))
point: POINT (0.623149 51.228577)
notes: The Maidstone Borough Council Tree Preservation Order No 10 of 1996 under Section 198 of the Town and Country Planning Act 1990 Group W1 - consisting of Sweet Chestnut, Oak,
organisation
entry-date: 1996-04-19
start-date: 1996-04-19
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.