You caused the multipolygon error, becasue you created a duplicate of a relation which was already there. I deleted the new relation you added to rectify the error. ---The health centre footprint is also not as accurate as it could be I used the building tools plugin, draw nodes and extrude tools to improve it and accounted for off nadir imagery when placing it. --- You correctly resolved a highway/building overlap. Please see Changeset: 164356401 for my resolution.
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            #REVIEWED_BAD #OSMCHA
            Published using OSMCha: https://osmcha.org/changesets/164328177
            