I upgraded my DNN version to 4.7 and now when I go to Admin, Skins, I get the following error (has anyone else seen this):

Error: Skins is currently unavailable.
DotNetNuke.Services.Exceptions.ModuleLoadException: Object reference not set to an instance of an object. ---> System.NullReferenceException: Object reference not set to an instance of an object. at DotNetNuke.UI.Skins.SkinDefaults..ctor(SkinDefaultType DefaultType) at DotNetNuke.Common.Globals.get_DefaultSkin() at DotNetNuke.Modules.Admin.Skins.EditSkins.isFallbackSkin(String skinPath) at DotNetNuke.Modules.Admin.Skins.EditSkins.ProcessSkins(String strFolderPath) at DotNetNuke.Modules.Admin.Skins.EditSkins.ShowSkins() at DotNetNuke.Modules.Admin.Skins.EditSkins.LoadSkins() at DotNetNuke.Modules.Admin.Skins.EditSkins.Page_Load(Object sender, EventArgs e) --- End of inner exception stack trace ---

What solved it in my case was to edit the "EditSkins.ascx.vb" located in the "admin > Skins"

Locate the following two functions inside the "Private Methods" Region

        Private Function isFallbackSkin(ByVal skinPath As String) As Boolean
            Dim strDefaultSkinPath As String = (Common.Globals.HostMapPath & SkinInfo.RootSkin + DefaultSkin.Folder).Replace("/", "\")
            If strDefaultSkinPath.EndsWith("\") Then
                strDefaultSkinPath = strDefaultSkinPath.Substring(0, strDefaultSkinPath.Length - 1)
            End If
            Return skinPath.IndexOf(strDefaultSkinPath, StringComparison.CurrentCultureIgnoreCase) <> -1
        End Function

        Private Function isFallbackContainer(ByVal skinPath As String) As Boolean
            Dim strDefaultContainerPath As String = (Common.Globals.HostMapPath & SkinInfo.RootContainer + DefaultSkin.Folder).Replace("/", "\")
            If strDefaultContainerPath.EndsWith("\") Then
                strDefaultContainerPath = strDefaultContainerPath.Substring(0, strDefaultContainerPath.Length - 1)
            End If
            Return skinPath.IndexOf(strDefaultContainerPath, StringComparison.CurrentCultureIgnoreCase) <> -1
        End Function

Replace the marked red text with: glbDefaultSkinFolder

Thanks dude you rock! That worked for me too!