| ERROR | Level string cannot be added to the hierarchy; the specified parent level string is already the parent of string |
| CAUSE | The level specified as the parent in the ADD_LEVEL_TO_HIERARCHY procedure could not be used, because it was the parent of another level within the hierarchy. |
| ACTION | In the ADD_LEVEL_TO_HIERARCHY procedure, specify a parent that is not already a parent of another level within a hierarchy. |