I have a site that is working perfectly and does everything right except one thing.

When you log in as host or administrator and try to go to the Skins page, I get this error, "Object reference not set to an instance of an object. ". 

Some details of the error are below.  It is almost like I am missing a skin or something but no matter what I do, I just can't fix this one.  Has anyone run across this or have any ideas?

Object reference not set to an instance of an object.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

Source Error:

Line 52: 
Line 53:         Private Function isFallbackSkin(ByVal skinPath As String) As Boolean
Line 54:             Dim strDefaultSkinPath As String = (Common.Globals.HostMapPath & SkinInfo.RootSkin + DefaultSkin.Folder).Replace("/", "\")
Line 55:             If strDefaultSkinPath.EndsWith("\") Then
Line 56:                 strDefaultSkinPath = strDefaultSkinPath.Substring(0, strDefaultSkinPath.Length - 1)

[NullReferenceException: Object reference not set to an instance of an object.]
   DotNetNuke.UI.Skins.SkinDefaults..ctor(SkinDefaultType DefaultType) +189
   DotNetNuke.Common.Globals.get_DefaultSkin() +31
   DotNetNuke.Modules.Admin.Skins.EditSkins.isFallbackSkin(String skinPath) in C:\HOME\notary\DnnSites\notaries2008prod.com\Admin\Skins\EditSkins.ascx.vb:54
   DotNetNuke.Modules.Admin.Skins.EditSkins.ProcessSkins(String strFolderPath) in C:\HOME\notary\DnnSites\notaries2008prod.com\Admin\Skins\EditSkins.ascx.vb:255
   DotNetNuke.Modules.Admin.Skins.EditSkins.ShowSkins() in C:\HOME\notary\DnnSites\notaries2008prod.com\Admin\Skins\EditSkins.ascx.vb:77
   DotNetNuke.Modules.Admin.Skins.EditSkins.LoadSkins() in C:\HOME\notary\DnnSites\notaries2008prod.com\Admin\Skins\EditSkins.ascx.vb:187
   DotNetNuke.Modules.Admin.Skins.EditSkins.Page_Load(Object sender, EventArgs e) in C:\HOME\notary\DnnSites\notaries2008prod.com\Admin\Skins\EditSkins.ascx.vb:558

Mike, I owe you one on this one.  I found the problem and it worked.  The problem was missing code in the dotnetnuke.config file as the post you sent explained.  I added back in the missing code and it fixed it.  Thanks for the help.  I knew it was somthing simple but I was tearing my hair out trying to find it.  Hours and hours of searching and voila, fixed in a minute.  Thanks again.  Rich