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AMD-00104:

Level "string" cannot be added to the hierarchy; parent and child parameters represent the same level
Cause: The same level name was specified for both the parent and the child parameters of the ADD_LEVEL_TO_HIERARCHY procedure.
Action: Determine which level should be the parent of the new level being added to the hierarchy. Specify the parent in the parent parameter and the new level in the child parameter of the ADD_LEVEL_TO_HIERARCHY procedure. Re-run the procedure.