Hi, Please see here:- https://tools.geofabrik.de/osmi/?view=geometry&lon=0.33394&lat=50.81932&zoom=18&baselayer=Geofabrik%20Standard&overlays=self_intersection_ways%2Cself_intersection_points%2Csingle_node_in_way%2Cduplicate_node_in_way

You've inadvertently introduced self-intersecting outlines. Also, there are now two walls, your new wall outline, and the existing wall=castle_wall. Could you resolve these problems, please?

Regards Bernard.