I just installed VS2012 Professional, it fails to open a web app developed with VS 2008 Pro with the following error, what's wrong with it? How do I fix it? Thank you very much.
Construction of frame content failed. Frame identifier: ST:0:0:{ecb7191a-597b-41f5-9843-03a4cf275dde} Frame caption: Exception details: System.ComponentModel.Composition.ImportCardinalityMismatchException: No exports were found that match the constraint: ContractName Microsoft.VisualStudio.Utilities.IContentTypeRegistryService RequiredTypeIdentity Microsoft.VisualStudio.Utilities.IContentTypeRegistryService at System.ComponentModel.Composition.Hosting.ExportProvider.GetExports(ImportDefinition definition, AtomicComposition atomicComposition) at System.ComponentModel.Composition.Hosting.ExportProvider.GetExportsCore(Type type, Type metadataViewType, String contractName, ImportCardinality cardinality) at System.ComponentModel.Composition.Hosting.ExportProvider.GetExportedValueCore[T](String contractName, ImportCardinality cardinality) at System.ComponentModel.Composition.Hosting.ExportProvider.GetExportedValue[T](String contractName) at System.ComponentModel.Composition.Hosting.ExportProvider.GetExportedValue[T]() at Microsoft.VisualStudio.ComponentModelHost.ComponentModel.GetService[T]() at Microsoft.VisualStudio.Editor.Implementation.EditorParts.get_ContentTypeRegistryService() at Microsoft.VisualStudio.Editor.Implementation.LanguageServiceToContentTypeMapper.MakeLanguageServiceContentTypes(SettingsStore settingsStore) at Microsoft.VisualStudio.Editor.Implementation.LanguageServiceToContentTypeMapper.InitLanguageServiceToContentTypeMapper(IServiceProvider serviceProvider, IComponentModel componentModel) at Microsoft.VisualStudio.Editor.Implementation.VsDocDataAdapter.SetSite(Object pUnkSite) at Microsoft.VisualStudio.Editor.Implementation.VsTextBufferAdapter.SetSite(Object pUnkSite) at System.Runtime.InteropServices.Marshal.ThrowExceptionForHRInternal(Int32 errorCode, IntPtr errorInfo) at Microsoft.VisualStudio.Platform.WindowManagement.WindowFrame.ConstructContent() VisualStudio 2014/02/04 18:29:06.847