The Error Inspector duplicates the name of the layer when the feature classes and the topology are created in the same session as validating the data and viewing the errors.

Workaround

Change the project options for geoprocessing to disable 'Add output dataset to an open map'. This setting takes effect when using the Create Feature Class geoprocessing tool or Python.

Unchecking this option does not affect the Create Feature Class tool when launched from the context menu in the Catalog View. That version of the tool has its own setting called 'Add output dataset to current map' which is enabled by default. Unchecking this setting ensures that the new feature class is not added to the open map upon completion.

Steps to Reproduce