How to Fix System.Collections.Generic.Dictionary`2.Insert Error

While playing with DotNetNuke 4.8 release locally i noticed that some issues from previous versions still remain unresolved.

For those who have errors like below:

AssemblyVersion: 04.08.00
PortalID: -1
PortalName:
UserID: -1
UserName:
ActiveTabID: -1
ActiveTabName:
RawURL: /dotnetnuke_2/Default.aspx
AbsoluteURL: /dotnetnuke_2/Default.aspx
AbsoluteURLReferrer:
UserAgent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.2; .NET CLR 1.1.4322; .NET CLR 2.0.50727)
DefaultDataProvider: DotNetNuke.Data.SqlDataProvider, DotNetNuke.SqlDataProvider
ExceptionGUID: dc815c95-5d42-467d-96ea-5ca34102ed88
InnerException: Object reference not set to an instance of an object.
FileName:
FileLineNumber: 0
FileColumnNumber: 0
Method: System.Collections.Generic.Dictionary`2.Insert
StackTrace:
Message: System.NullReferenceException: Object reference not set to an instance of an object. at System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add) at System.Collections.Generic.Dictionary`2.set_Item(TKey key, TValue value) at DotNetNuke.Entities.Portals.PortalController.AddPortalDictionary(Int32 portalId, Int32 tabId) in G:\DNNWebs\dotnetnuke_2\Library\Components\Portal\PortalController.vb:line 208 at DotNetNuke.Entities.Tabs.TabController.FillTabInfo(IDataReader dr, Boolean CheckForOpenDataReader, Boolean CheckForLegacyFields) in G:\DNNWebs\dotnetnuke_2\Library\Components\Tabs\TabController.vb:line 136 at DotNetNuke.Entities.Tabs.TabController.FillTabInfoCollection(IDataReader dr, Boolean CheckForLegacyFields) in G:\DNNWebs\dotnetnuke_2\Library\Components\Tabs\TabController.vb:line 151
Source:
Server Name: 2003R2SP2

consider applying following workaround;

1. Login as Host to your portal;

2. Go to Host > SQL page and paste following command then hit Execute.

UPDATE DesktopModules
SET SupportedFeatures = 0
WHERE SupportedFeatures = -1

if you are using DNN as object qualifier use the code below then hit Execute.

UPDATE DNN_DesktopModules
SET SupportedFeatures = 0
WHERE SupportedFeatures = -1

Resource: http://www.mitchelsellers.com/Blogs/tabid/54/articleType/ArticleView/articleId/111/Default.aspx