I know I've seen this error, or ones similar, all over the place, but I have not been able to find a definitive answer. Scenario: I am logged in as HOST. I CAN access Admin/Extensions, but I can not access Host/Extensions. the ASP.Net account has full access to the web folder and .NET Framework 3.5 SP1 is installed on the server. Everything else works correctly. The following error appears: A critical error has occurred. Object reference not set to an instance of an object. And what follows is the text from the log viewer: AssemblyVersion: 5.2.1 PortalID: 1 PortalName: GWHTestWebSite UserID: 1 UserName: host ActiveTabID: 36 ActiveTabName: Extensions RawURL: /tabid/36/portalid/1/Default.aspx AbsoluteURL: /Default.aspx AbsoluteURLReferrer: http://web.gwh.org/default.aspx UserAgent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; InfoPath.1; .NET CLR 2.0.50727; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729) DefaultDataProvider: DotNetNuke.Data.SqlDataProvider, DotNetNuke.SqlDataProvider ExceptionGUID: cc067cec-c7d0-4a9f-91f7-5bd88519f654 InnerException: Object reference not set to an instance of an object. FileName: FileLineNumber: 0 FileColumnNumber: 0 Method: DotNetNuke.Services.Installer.Packages.PackageController.CanDeletePackage StackTrace: Message: DotNetNuke.Services.Exceptions.PageLoadException: Object reference not set to an instance of an object. ---> System.NullReferenceException: Object reference not set to an instance of an object. at DotNetNuke.Services.Installer.Packages.PackageController.CanDeletePackage(PackageInfo package, PortalSettings portalSettings) at DotNetNuke.Modules.Admin.Extensions.Extensions.grdPackages_ItemDataBound(Object sender, DataGridItemEventArgs e) at System.Web.UI.WebControls.DataGrid.OnItemDataBound(DataGridItemEventArgs e) at System.Web.UI.WebControls.DataGrid.CreateItem(Int32 itemIndex, Int32 dataSourceIndex, ListItemType itemType, Boolean dataBind, Object dataItem, DataGridColumn[] columns, TableRowCollection rows, PagedDataSource pagedDataSource) at System.Web.UI.WebControls.DataGrid.CreateControlHierarchy(Boolean useDataSource) at System.Web.UI.WebControls.BaseDataList.OnDataBinding(EventArgs e) at System.Web.UI.WebControls.BaseDataList.DataBind() at DotNetNuke.Modules.Admin.Extensions.Extensions.BindGrid() at DotNetNuke.Modules.Admin.Extensions.Extensions.OnLoad(EventArgs e) at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) --- End of inner exception stack trace --- Source: Server Name: GWHWEB Any help or guidance would be appreciated.

Is this a new installation, or is it an upgrade? Can you verify that you have SQL Server 2005 or higher?

Yes, it's a clean/new installation and we installed SQL Server 2008 to go along with the DNN 5.2 installation.

As this is a clean/new installation, I'd suggest that you delete the web directory and the database and start over.

If you have created a portal that you want to save, export it and save the files that are created before deleting everything.

Hi, Not sure if this will help you but I thought I'd share. I had this exact error not long ago. The problem was due to the fact the we manually deleted records from the Skins and SkinPackages tables without removing related records from the Packages table. When the Extensions module would try and load there was no reference to the skin and container records that should have been there. We did this for skin installation testing. We simply reloaded those two tables from a prior backup and the problem was solved. So, if you manually added, removed or even updated records in the source tables this could be the source of your problem. Hope this helps...

Yes, you are absolutely correct. However, prior to your response I was talking through this problem with a colleague and once we realized (a real DUH moment!) that DNN is based on a relational database, we followed the relations of the tables associated with skins and containers and determined that one of the tables was referencing skins that were no longer installed AND needed related entries in another table. Well, as you pointed out that one table was incomplete so we manually reenterred the skin names and containers along with the correct data in the related field and taaa-daaa the extension page worked. Restoring from a previous backup would have been easier, but there's something really fun about seeing how it all works. Thanks!

Glad to hear you got it working and thanks for posting the solution