my VS2008 designer cannot display one of my RadWindow, I see only a white square and in my output window I have the following error:
Failed to instantiate type Telerik.Windows.Controls.Design.Common.MetadataRegistrationBase during IRegisterMetadata load for metadata assembly Telerik.Windows.Controls.VisualStudio.Design, Version=2011.3.1220.35, Culture=neutral, PublicKeyToken=5803cfa389c90ce7.Failed to instantiate type Telerik.Windows.Controls.Design.Common.MetadataRegistrationBase during IRegisterMetadata load for metadata assembly Telerik.Windows.Controls.Input.VisualStudio.Design, Version=2011.3.1220.35, Culture=neutral, PublicKeyToken=5803cfa389c90ce7.Failed to instantiate type Telerik.Windows.Controls.Design.Common.MetadataRegistrationBase during IRegisterMetadata load for metadata assembly Telerik.Windows.Controls.Navigation.VisualStudio.Design, Version=2011.3.1220.35, Culture=neutral, PublicKeyToken=5803cfa389c90ce7.Failed to instantiate type Telerik.Windows.Controls.Design.Common.MetadataRegistrationBase during IRegisterMetadata load for metadata assembly Telerik.Windows.Controls.RichTextBoxUI.VisualStudio.Design, Version=2011.3.1220.35, Culture=neutral, PublicKeyToken=5803cfa389c90ce7.Failed to instantiate type Telerik.Windows.Controls.Design.Common.MetadataRegistrationBase during IRegisterMetadata load for metadata assembly Telerik.Windows.Documents.VisualStudio.Design, Version=2011.3.1220.35, Culture=neutral, PublicKeyToken=5803cfa389c90ce7.Failed to instantiate type Telerik.Windows.Controls.Design.Common.MetadataRegistrationBase during IRegisterMetadata load for metadata assembly Telerik.Windows.Controls.VisualStudio.Design, Version=2011.3.1220.35, Culture=neutral, PublicKeyToken=5803cfa389c90ce7.Failed to instantiate type Telerik.Windows.Controls.Design.Common.MetadataRegistrationBase during IRegisterMetadata load for metadata assembly Telerik.Windows.Controls.Docking.VisualStudio.Design, Version=2011.3.1220.35, Culture=neutral, PublicKeyToken=5803cfa389c90ce7.Failed to instantiate type Telerik.Windows.Controls.Design.Common.MetadataRegistrationBase during IRegisterMetadata load for metadata assembly Telerik.Windows.Controls.Navigation.VisualStudio.Design, Version=2011.3.1220.35, Culture=neutral, PublicKeyToken=5803cfa389c90ce7.Failed to instantiate type Telerik.Windows.Controls.Design.Common.MetadataRegistrationBase during IRegisterMetadata load for metadata assembly Telerik.Windows.Controls.Input.VisualStudio.Design, Version=2011.3.1220.35, Culture=neutral, PublicKeyToken=5803cfa389c90ce7.Failed to instantiate type Telerik.Windows.Controls.Design.Common.MetadataRegistrationBase during IRegisterMetadata load for metadata assembly Telerik.Windows.Controls.ScheduleView.VisualStudio.Design, Version=2011.2.712.35, Culture=neutral, PublicKeyToken=5803cfa389c90ce7.Failed to instantiate type Telerik.Windows.Controls.Design.Common.MetadataRegistrationBase during IRegisterMetadata load for metadata assembly Telerik.Windows.Controls.Input.VisualStudio.Design, Version=2011.2.712.35, Culture=neutral, PublicKeyToken=5803cfa389c90ce7.Failed to instantiate type Telerik.Windows.Controls.Design.Common.MetadataRegistrationBase during IRegisterMetadata load for metadata assembly Telerik.Windows.Controls.VisualStudio.Design, Version=2011.2.712.35, Culture=neutral, PublicKeyToken=5803cfa389c90ce7.Failed to instantiate type Telerik.Windows.Controls.Design.Common.MetadataRegistrationBase during IRegisterMetadata load for metadata assembly Telerik.Windows.Controls.Navigation.VisualStudio.Design, Version=2011.2.712.35, Culture=neutral, PublicKeyToken=5803cfa389c90ce7.Failed to instantiate type Telerik.Windows.Controls.Design.Common.MetadataRegistrationBase during IRegisterMetadata load for metadata assembly Telerik.Windows.Documents.VisualStudio.Design, Version=2011.3.1220.35, Culture=neutral, PublicKeyToken=5803cfa389c90ce7.Failed to instantiate type Telerik.Windows.Controls.Design.Common.MetadataRegistrationBase during IRegisterMetadata load for metadata assembly Telerik.Windows.Controls.VisualStudio.Design, Version=2011.3.1220.35, Culture=neutral, PublicKeyToken=5803cfa389c90ce7.Failed to instantiate type Telerik.Windows.Controls.Design.Common.MetadataRegistrationBase during IRegisterMetadata load for metadata assembly Telerik.Windows.Controls.Docking.VisualStudio.Design, Version=2011.3.1220.35, Culture=neutral, PublicKeyToken=5803cfa389c90ce7.Failed to instantiate type Telerik.Windows.Controls.Design.Common.MetadataRegistrationBase during IRegisterMetadata load for metadata assembly Telerik.Windows.Controls.Navigation.VisualStudio.Design, Version=2011.3.1220.35, Culture=neutral, PublicKeyToken=5803cfa389c90ce7.Failed to instantiate type Telerik.Windows.Controls.Design.Common.MetadataRegistrationBase during IRegisterMetadata load for metadata assembly Telerik.Windows.Controls.Input.VisualStudio.Design, Version=2011.3.1220.35, Culture=neutral, PublicKeyToken=5803cfa389c90ce7.Failed to instantiate type Telerik.Windows.Controls.Design.Common.MetadataRegistrationBase during IRegisterMetadata load for metadata assembly Telerik.Windows.Controls.RichTextBoxUI.VisualStudio.Design, Version=2011.3.1220.35, Culture=neutral, PublicKeyToken=5803cfa389c90ce7.Failed to instantiate type Telerik.Windows.Controls.Design.Common.MetadataRegistrationBase during IRegisterMetadata load for metadata assembly Telerik.Windows.Documents.VisualStudio.Design, Version=2011.3.1220.35, Culture=neutral, PublicKeyToken=5803cfa389c90ce7.