Enable Command problem

Hi everyone,

In my C# addin, I limit some command to some document type:

public int Command1Enable()

{

    var doc = (ModelDoc2)App.ActiveDoc;

    if (doc != null)

    {

        var type = (swDocumentTypes_e)doc.GetType();

        if (type == swDocumentTypes_e.swDocPART)

        {

            return 1;

        }

    }

    return 0;

}

Everything works great, when I switch between different document types (Ctrl+Tab), Command1 button state is updated.

... Until I create a new drawing doc:

After that, when I switch between different document types (Ctrl+Tab), Command1 button state is no longer updated.

Do you have the problem too?

SolidWorks 2017 SP2.

Regards

SolidworksApi macros