Sql Server 2008 - Error: Undefined object reference for an object instance?

Question

I was using sql server 2005, after doing the update, all databases does not allow the display of tables in Design mode, and does not let create new tables.

I tried to make the creation of a table in visual way is generated me this error, anyone knows how to solve? Thanks.

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Referência de objeto não definida para uma instância de um objeto. (SQLEditors)

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Local do Programa:

   em Microsoft.SqlServer.Management.UI.VSIntegration.Editors.VsDataDesignerNode.CreateDesigner()
   em Microsoft.SqlServer.Management.UI.VSIntegration.Editors.VsDataDesignerNode.Open()
   em Microsoft.SqlServer.Management.UI.VSIntegration.Editors.VirtualProject.CreateDesigner(Urn origUrn, DocumentType editorType, DocumentOptions aeOptions, IManagedConnection con, String fileName)
   em Microsoft.SqlServer.Management.UI.VSIntegration.Editors.VirtualProject.Microsoft.SqlServer.Management.UI.VSIntegration.Editors.ISqlVirtualProject.CreateDesigner(Urn origUrn, DocumentType editorType, DocumentOptions aeOptions, IManagedConnection con, String fileName)
   em Microsoft.SqlServer.Management.UI.VSIntegration.Editors.ISqlVirtualProject.CreateDesigner(Urn origUrn, DocumentType editorType, DocumentOptions aeOptions, IManagedConnection con, String fileName)
   em Microsoft.SqlServer.Management.UI.VSIntegration.Editors.ScriptFactory.CreateDesigner(DocumentType editorType, DocumentOptions aeOptions, Urn parentUrn, IManagedConnection mc, String fileName)
   em Microsoft.SqlServer.Management.UI.VSIntegration.Editors.VsDocumentMenuItem.CreateDesignerWindow(IManagedConnection mc, DocumentOptions options)