If you already assets in your Canto library prior to setting up your Duplicate Check feature, you still can run a Duplicate Check. See below for steps on how to do this.
1) Go to Settings > Configuration Options > Duplicate Check > select Check for Duplicates. Please note that the Duplicate Check will run under the settings listed above:
2) When the Duplicate Check is complete, a folder, titled Duplicates, will appear in your asset tree where you can inspect the duplicate assets and take the next best for your workflow to consolidate assets.
Note: the Duplicates folder will contain all duplicated files and are still located in their respect folders and albums.