Localhost install on Vista, 4.9.  I was in "Host, Skins" and clicked on "reset to default" or something like.  Public displays fine, login is fine but if I click on "Host" or "Site" I get this error and nothing works.   My brain is already tied in knots from skins and I can't determine what the problem could be.

[code]

Line 554:
Line 555:            ' set skin id to an explicit short name to reduce page payload and make it standards compliant
Line 556:            ctlSkin.ID = "dnn"
Line 557:
Line 558:            'Manage disabled pages

Source File: C:\inetpub\wwwroot\DNN\Default.aspx.vb    Line: 556

[NullReferenceException: Object reference not set to an instance of an object.]
   DotNetNuke.Framework.DefaultPage.Page_Init(Object sender, EventArgs e) in C:\inetpub\wwwroot\DNN\Default.aspx.vb:556
   System.Web.UI.Control.OnInit(EventArgs e) +99
   System.Web.UI.Page.OnInit(EventArgs e) +12
   DotNetNuke.Framework.PageBase.OnInit(EventArgs e) +94
   System.Web.UI.Control.InitRecursive(Control namingContainer) +333
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +378

[PageLoadException: Object reference not set to an instance of an object.]
   DotNetNuke.Services.Exceptions.Exceptions.ProcessPageLoadException(Exception exc, String URL) +324
   DotNetNuke.Framework.PageBase.Page_Error(Object Source, EventArgs e) +380
   System.Web.UI.TemplateControl.OnError(EventArgs e) +8689450
   System.Web.UI.Page.HandleError(Exception e) +84
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +6776
   System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +242
   System.Web.UI.Page.ProcessRequest() +80
   System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context) +21
   System.Web.UI.Page.ProcessRequest(HttpContext context) +49
   ASP.default_aspx.ProcessRequest(HttpContext context) +37
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +181
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +75
[/code]

What in the world could have happened from changing a skin to cause this level of problem?

There hasn't been sitting any post in the public forums awaiting moderation for more than 6 hours the past days, except it was posted to the "Announce it!" forum, which is moderated by a few admins only. Either there has been a technical problem or your observation has been wrong (maybe the notification email has been delayed only?)