Hi Dileep,

The duplicate key is almost certainly coming from the repository descriptor registration, not from the Settings.Add("repositoryKey", …) line on the component.

In this Site Settings pattern there are two different concepts:

1. Component setting name

Settings.Add(new Setting("repositoryKey", GlobalSettingsRepositoryDescriptor.RepositoryKey));

Here, "repositoryKey" is just the setting name inside the component.
You can reuse this name across multiple components - that’s fine.

2. Content repository descriptor key

In your ContentRepositoryDescriptorBase implementation you usually have something like:

public class GlobalSettingsRepositoryDescriptor : ContentRepositoryDescriptorBase
{
    public static string RepositoryKey => "globalsettings";

    public override string Key => RepositoryKey;
    // ...
}

This Key is what Optimizely uses internally in a dictionary of descriptors.
This must be unique across all descriptors.

If two descriptors return the same Key, you get the classic:

An item with the same key has already been added.

…even if you changed the string used by the component setting.

I think you just need to check in your SettingsV2ContentRepositoryDescriptor

Make sure your new descriptor has its own constant and that both RepositoryKey and Key are unique, e.g.:

[ServiceConfiguration(typeof(IContentRepositoryDescriptor))]
public class SettingsV2ContentRepositoryDescriptor : ContentRepositoryDescriptorBase
{
    public static string RepositoryKey => "sitewidesettingsv2";

    public override string Key => RepositoryKey;   // Must be unique!

    // Other overrides...
    // ContainedTypes, CreatableTypes, Roots, Name, SortOrder, etc.
}

If you only changed RepositoryKey but left Key returning the old constant (or copied the old descriptor without updating this), you’ll still get the duplicate key exception.

Once that’s true, this part of your component is fine:

Settings.Add(new Setting("repositoryKey", SettingsV2ContentRepositoryDescriptor.RepositoryKey));

You don’t need to change the setting name "repositoryKey" – the important bit is that the descriptor’s Key is unique.

Hope this will help!