If the error occurs immediately after the Synchronise dm_placement_addresses were placed with Parents step this is a known issue which occurs in the following circumstances:
A placement is recorded for a child where the placement type is not mapped to the Child Placed with Parents filter.
The populate script is run and a row is entered for the placement into DM_PLACEMENT_ADDRESSES.
The placement type is then amended to a placement type which is mapped to the Child Placed with Parents.
The populate script is re-run (which attempts to add an additional row for the placement within DM_PLACEMENT_ADDRESSES).
The populate job will be updated in Mosaic Reports 24.1.0.0 to update the IS_PLACED_WITH_PARENTS field within the original row to Y (rather than attempting to insert a new row).