Custom feature switch : Invalid column name

I'm trying to implement a custom feature switch in the Enable/Disable Features screen (CS101000). 
In my extension library, I added the following code to a new file named FeaturesSetExt.cs:

namespace PX.Objects.CS
{
    public class FeaturesSetExt : PXCacheExtension<PX.Objects.CS.FeaturesSet>
    {
        #region UsrCustomSwitch
        [PXDefault(false, PersistingCheck = PXPersistingCheck.Nothing)]
        [Feature(false, DisplayName = "Custom Feature")]
        public bool? UsrCustomSwitch { get; set; }
        public abstract class usrCustomSwitch : PX.Data.BQL.BqlBool.Field<usrCustomSwitch> { }
        #endregion
    }
}

I also added a new Features.xml file with the following content:

<?xml version="1.0" encoding="utf-8"?>
<Features Type="MyExtLibrary.FeaturesSetExt" Key="0">
    <Feature Name="UsrCustomSwitch">
        <Access ScreenID="SA101000"/>
        <Access ScreenID="SA201000"/>
        <Access ScreenID="SA401000"/>
        <Access ScreenID="SA501000"/>
        <Access ScreenID="SA502000"/>
        <Access ScreenID="SA503000"/>
    </Feature>
</Features>

I set the Build Action of Features.xml to Embedded Resource.

The project builds successfully, and I published the customization project. 
However, when I navigate to the Enable/Disable Features screen, I receive the following error:

Invalid column name '[FeaturesSet].[UsrCustomSwitch]'

Am I did anything wrong? Or missed something ?

any help would be appreciated .

Thank you