Ok. The exception is generated when the deseralization of an object is attempted (a break point is placed into the deserialization constructor). When the file .cs is called (for show the code at the break point), the exceptions are fired. A exception is fired when the code implements serialization. Unhandled Exception: JetBrains.ReSharper.Util.InternalErrorException: An exception has occurred during change propagation process ---> System.InvalidCastException: QueryInterface for interface JetBrains.ReSharper.Metadata.Access.IMetaDataAssemblyImport failed. at JetBrains.ReSharper.Metadata.Access.IMetaDataAssemblyImport.EnumAssemblyRefs(UInt32& phEnum, UInt32[] rAssemblyRefs, Int32 cMax, Int32& pcTokens) at JetBrains.ReSharper.Metadata.Access.Impl.MetadataAssemblyInfo.GetAssebmlyRefs() in c:\TEMP\tmpABD0.tmp\src\Metadata\src\Access\Impl\MetadataAssemblyInfo.cs:line 109 at JetBrains.ReSharper.Metadata.Access.Impl.MetadataAssemblyInfo.GetReferencedAssembliesNames() in c:\TEMP\tmpABD0.tmp\src\Metadata\src\Access\Impl\MetadataAssemblyInfo.cs:line 68 at JetBrains.ReSharper.Psi.Impl.Caches.AssemblyLoader.References(IAssembly assembly) in c:\TEMP\tmpABD0.tmp\src\Psi\src\impl\caches\changes\AssemblyLoader.cs:line 97 at JetBrains.ReSharper.Psi.Impl.Caches.ModuleManagerPostChangeProcessor.References(AssemblyLoader loader, IAssembly assembly) in c:\TEMP\tmpABD0.tmp\src\Psi\src\impl\caches\modulemanager\ModuleManagerPostChangeProcessor.cs:line 134 at JetBrains.ReSharper.Psi.Impl.Caches.ModuleManagerPostChangeProcessor.RefreshProjectDependencies(AssemblyLoader loader) in c:\TEMP\tmpABD0.tmp\src\Psi\src\impl\caches\modulemanager\ModuleManagerPostChangeProcessor.cs:line 169 at JetBrains.ReSharper.Psi.Impl.Caches.ModuleManagerPostChangeProcessor.ComputeChangeUnits(IChangeMap changeMap) in c:\TEMP\tmpABD0.tmp\src\Psi\src\impl\caches\modulemanager\ModuleManagerPostChangeProcessor.cs:line 38 at JetBrains.ReSharper.Shell.Impl.MyChangePropagationHelper.VisitProvider(IChangeProvider changeProvider, IChangeProcessor[] dependentProcessors) in c:\TEMP\tmpABD0.tmp\src\Shell\src\impl\changes\ChangeManagerImpl.cs:line 228 --- End of inner exception stack trace --- at JetBrains.ReSharper.Util.Logger.LogExceptionEx(Exception, String, Boolean) in c:\TEMP\tmpABD0.tmp\src\Util\src\Logger.cs:line 285 column 9 at JetBrains.ReSharper.Util.Logger.LogException(String, Exception) in c:\TEMP\tmpABD0.tmp\src\Util\src\Logger.cs:line 302 column 5 at JetBrains.ReSharper.Shell.Impl.MyChangePropagationHelper.VisitProvider(IChangeProvider, IChangeProcessor[]) in c:\TEMP\tmpABD0.tmp\src\Shell\src\impl\changes\ChangeManagerImpl.cs:line 232 column 15 at JetBrains.ReSharper.Shell.Impl.MyGraphVisitor.VisitNode(IChangeProvider) in c:\TEMP\tmpABD0.tmp\src\Shell\src\impl\changes\ChangeManagerImpl.cs:line 147 column 55 at JetBrains.ReSharper.Shell.Impl.MyGraphVisitor.VisitNode(IChangeProvider) in c:\TEMP\tmpABD0.tmp\src\Shell\src\impl\changes\ChangeManagerImpl.cs:line 148 column 11 at JetBrains.ReSharper.Shell.Impl.MyGraphVisitor.VisitNode(IChangeProvider) in c:\TEMP\tmpABD0.tmp\src\Shell\src\impl\changes\ChangeManagerImpl.cs:line 148 column 11 at JetBrains.ReSharper.Shell.Impl.MyGraphVisitor.VisitNode(IChangeProvider) in c:\TEMP\tmpABD0.tmp\src\Shell\src\impl\changes\ChangeManagerImpl.cs:line 148 column 11 at JetBrains.ReSharper.Shell.Impl.MyGraphVisitor.VisitNode(IChangeProvider) in c:\TEMP\tmpABD0.tmp\src\Shell\src\impl\changes\ChangeManagerImpl.cs:line 148 column 11 at JetBrains.ReSharper.Shell.Impl.MyChangePropagationHelper.Run(IProgressIndicator) in c:\TEMP\tmpABD0.tmp\src\Shell\src\impl\changes\ChangeManagerImpl.cs:line 202 column 9 at JetBrains.ReSharper.Shell.Progress.TaskHelper.Run() in c:\TEMP\tmpABD0.tmp\src\Shell\src\Progress\ProgressWindow.cs:line 419 column 11 at JetBrains.ReSharper.Shell.Progress.AsyncTaskHelper.ThreadFunc() in c:\TEMP\tmpABD0.tmp\src\Shell\src\Progress\ProgressWindow.cs:line 466 column 7 Second exception: JetBrains.ReSharper.Util.InternalErrorException: An exception has occurred ---> System.NullReferenceException: Object reference not set to an instance of an object. at JetBrains.ReSharper.Psi.Impl.Caches.CompiledCodeProcessorBase.Process() in c:\TEMP\tmpABD0.tmp\src\Psi\src\impl\caches\symbolcache\CompiledCodeProcessorBase.cs:line 22 at JetBrains.ReSharper.Psi.Impl.Caches.SymbolCachePostChangeProcessor.OnItemAdded(CacheChangeDelta delta) in c:\TEMP\tmpABD0.tmp\src\Psi\src\impl\caches\symbolcache\changes\SymbolCachePostChangeProcessor.cs:line 229 at JetBrains.ReSharper.Psi.Impl.Caches.PersistCacheDeltaChangeProcessor.ItemAdded(CacheChangeDelta delta) in c:\TEMP\tmpABD0.tmp\src\Psi\src\impl\caches\changes\PersistCacheDeltaChangeProcessor.cs:line 92 at JetBrains.ReSharper.Psi.Impl.Caches.SymbolCachePostChangeProcessor.ItemAdded(CacheChangeDelta delta) in c:\TEMP\tmpABD0.tmp\src\Psi\src\impl\caches\symbolcache\changes\SymbolCachePostChangeProcessor.cs:line 90 at JetBrains.ReSharper.Psi.Impl.Caches.AddCacheChangeDelta.Accept(CacheDeltaChangeProcessor processor) in c:\TEMP\tmpABD0.tmp\src\Psi\src\impl\caches\changes\CacheChangeDelta.cs:line 81 at JetBrains.ReSharper.Psi.Impl.Caches.CacheDeltaChangeProcessor.ProcessChangeUnit(IChangeUnit changeUnit, IDictionary temporaryData) in c:\TEMP\tmpABD0.tmp\src\Psi\src\impl\caches\changes\CacheDeltaChangeProcessor.cs:line 29 at JetBrains.ReSharper.Shell.Impl.MyChangePropagationHelper.VisitProvider(IChangeProvider changeProvider, IChangeProcessor[] dependentProcessors) in c:\TEMP\tmpABD0.tmp\src\Shell\src\impl\changes\ChangeManagerImpl.cs:line 261 at JetBrains.ReSharper.Shell.Impl.MyGraphVisitor.VisitNode(IChangeProvider changeProvider) in c:\TEMP\tmpABD0.tmp\src\Shell\src\impl\changes\ChangeManagerImpl.cs:line 146 at JetBrains.ReSharper.Shell.Impl.MyGraphVisitor.VisitNode(IChangeProvider changeProvider) in c:\TEMP\tmpABD0.tmp\src\Shell\src\impl\changes\ChangeManagerImpl.cs:line 148 at JetBrains.ReSharper.Shell.Impl.MyGraphVisitor.VisitNode(IChangeProvider changeProvider) in c:\TEMP\tmpABD0.tmp\src\Shell\src\impl\changes\ChangeManagerImpl.cs:line 148 at JetBrains.ReSharper.Shell.Impl.MyChangePropagationHelper.Run(IProgressIndicator progressIndicator) in c:\TEMP\tmpABD0.tmp\src\Shell\src\impl\changes\ChangeManagerImpl.cs:line 201 at JetBrains.ReSharper.Shell.Progress.TaskHelper.Run() in c:\TEMP\tmpABD0.tmp\src\Shell\src\Progress\ProgressWindow.cs:line 419 at JetBrains.ReSharper.Shell.Progress.AsyncTaskHelper.ThreadFunc() in c:\TEMP\tmpABD0.tmp\src\Shell\src\Progress\ProgressWindow.cs:line 465 --- End of inner exception stack trace --- at JetBrains.ReSharper.Util.Logger.LogExceptionEx(Exception, String, Boolean) in c:\TEMP\tmpABD0.tmp\src\Util\src\Logger.cs:line 285 column 9 at JetBrains.ReSharper.Util.Logger.LogException(Exception) in c:\TEMP\tmpABD0.tmp\src\Util\src\Logger.cs:line 297 column 5 at JetBrains.ReSharper.Shell.ShellBase.OnUnhandledException(Exception) in c:\TEMP\tmpABD0.tmp\src\Shell\src\ShellBase.cs:line 121 column 5 at JetBrains.ReSharper.Shell.UIApplicationShell.CurrentDomain_UnhandledException(Object, UnhandledExceptionEventArgs) in c:\TEMP\tmpABD0.tmp\src\Shell\src\UIApplicationShell.cs:line 447 column 5 at System.UnhandledExceptionEventHandler.Invoke(Object, UnhandledExceptionEventArgs) at System.AppDomain.OnUnhandledExceptionEvent(Object, Boolean) at JetBrains.ReSharper.Psi.Impl.Caches.CompiledCodeProcessorBase.Process() in c:\TEMP\tmpABD0.tmp\src\Psi\src\impl\caches\symbolcache\CompiledCodeProcessorBase.cs:line 22 column 38 at JetBrains.ReSharper.Psi.Impl.Caches.SymbolCachePostChangeProcessor.OnItemAdded(CacheChangeDelta) in c:\TEMP\tmpABD0.tmp\src\Psi\src\impl\caches\symbolcache\changes\SymbolCachePostChangeProcessor.cs:line 232 column 5 at JetBrains.ReSharper.Psi.Impl.Caches.PersistCacheDeltaChangeProcessor.ItemAdded(CacheChangeDelta) in c:\TEMP\tmpABD0.tmp\src\Psi\src\impl\caches\changes\PersistCacheDeltaChangeProcessor.cs:line 94 column 5 at JetBrains.ReSharper.Psi.Impl.Caches.SymbolCachePostChangeProcessor.ItemAdded(CacheChangeDelta) in c:\TEMP\tmpABD0.tmp\src\Psi\src\impl\caches\symbolcache\changes\SymbolCachePostChangeProcessor.cs:line 91 column 5 at JetBrains.ReSharper.Psi.Impl.Caches.AddCacheChangeDelta.Accept(CacheDeltaChangeProcessor) in c:\TEMP\tmpABD0.tmp\src\Psi\src\impl\caches\changes\CacheChangeDelta.cs:line 82 column 5 at JetBrains.ReSharper.Psi.Impl.Caches.CacheDeltaChangeProcessor.ProcessChangeUnit(IChangeUnit, IDictionary) in c:\TEMP\tmpABD0.tmp\src\Psi\src\impl\caches\changes\CacheDeltaChangeProcessor.cs:line 30 column 7 at JetBrains.ReSharper.Shell.Impl.MyChangePropagationHelper.VisitProvider(IChangeProvider, IChangeProcessor[]) in c:\TEMP\tmpABD0.tmp\src\Shell\src\impl\changes\ChangeManagerImpl.cs:line 261 column 17 at JetBrains.ReSharper.Shell.Impl.MyGraphVisitor.VisitNode(IChangeProvider) in c:\TEMP\tmpABD0.tmp\src\Shell\src\impl\changes\ChangeManagerImpl.cs:line 147 column 55 at JetBrains.ReSharper.Shell.Impl.MyGraphVisitor.VisitNode(IChangeProvider) in c:\TEMP\tmpABD0.tmp\src\Shell\src\impl\changes\ChangeManagerImpl.cs:line 148 column 11 at JetBrains.ReSharper.Shell.Impl.MyGraphVisitor.VisitNode(IChangeProvider) in c:\TEMP\tmpABD0.tmp\src\Shell\src\impl\changes\ChangeManagerImpl.cs:line 148 column 11 at JetBrains.ReSharper.Shell.Impl.MyChangePropagationHelper.Run(IProgressIndicator) in c:\TEMP\tmpABD0.tmp\src\Shell\src\impl\changes\ChangeManagerImpl.cs:line 202 column 9 at JetBrains.ReSharper.Shell.Progress.TaskHelper.Run() in c:\TEMP\tmpABD0.tmp\src\Shell\src\Progress\ProgressWindow.cs:line 419 column 11 at JetBrains.ReSharper.Shell.Progress.AsyncTaskHelper.ThreadFunc() in c:\TEMP\tmpABD0.tmp\src\Shell\src\Progress\ProgressWindow.cs:line 466 column 7 Unexpected error: at JetBrains.ReSharper.Psi.Impl.Caches.CompiledCodeProcessorBase.Process() in c:\TEMP\tmpABD0.tmp\src\Psi\src\impl\caches\symbolcache\CompiledCodeProcessorBase.cs:line 22 at JetBrains.ReSharper.Psi.Impl.Caches.SymbolCachePostChangeProcessor.OnItemAdded(CacheChangeDelta delta) in c:\TEMP\tmpABD0.tmp\src\Psi\src\impl\caches\symbolcache\changes\SymbolCachePostChangeProcessor.cs:line 229 at JetBrains.ReSharper.Psi.Impl.Caches.PersistCacheDeltaChangeProcessor.ItemAdded(CacheChangeDelta delta) in c:\TEMP\tmpABD0.tmp\src\Psi\src\impl\caches\changes\PersistCacheDeltaChangeProcessor.cs:line 92 at JetBrains.ReSharper.Psi.Impl.Caches.SymbolCachePostChangeProcessor.ItemAdded(CacheChangeDelta delta) in c:\TEMP\tmpABD0.tmp\src\Psi\src\impl\caches\symbolcache\changes\SymbolCachePostChangeProcessor.cs:line 90 at JetBrains.ReSharper.Psi.Impl.Caches.AddCacheChangeDelta.Accept(CacheDeltaChangeProcessor processor) in c:\TEMP\tmpABD0.tmp\src\Psi\src\impl\caches\changes\CacheChangeDelta.cs:line 81 at JetBrains.ReSharper.Psi.Impl.Caches.CacheDeltaChangeProcessor.ProcessChangeUnit(IChangeUnit changeUnit, IDictionary temporaryData) in c:\TEMP\tmpABD0.tmp\src\Psi\src\impl\caches\changes\CacheDeltaChangeProcessor.cs:line 29 at JetBrains.ReSharper.Shell.Impl.MyChangePropagationHelper.VisitProvider(IChangeProvider changeProvider, IChangeProcessor[] dependentProcessors) in c:\TEMP\tmpABD0.tmp\src\Shell\src\impl\changes\ChangeManagerImpl.cs:line 261 at JetBrains.ReSharper.Shell.Impl.MyGraphVisitor.VisitNode(IChangeProvider changeProvider) in c:\TEMP\tmpABD0.tmp\src\Shell\src\impl\changes\ChangeManagerImpl.cs:line 146 at JetBrains.ReSharper.Shell.Impl.MyGraphVisitor.VisitNode(IChangeProvider changeProvider) in c:\TEMP\tmpABD0.tmp\src\Shell\src\impl\changes\ChangeManagerImpl.cs:line 148 at JetBrains.ReSharper.Shell.Impl.MyGraphVisitor.VisitNode(IChangeProvider changeProvider) in c:\TEMP\tmpABD0.tmp\src\Shell\src\impl\changes\ChangeManagerImpl.cs:line 148 at JetBrains.ReSharper.Shell.Impl.MyChangePropagationHelper.Run(IProgressIndicator progressIndicator) in c:\TEMP\tmpABD0.tmp\src\Shell\src\impl\changes\ChangeManagerImpl.cs:line 201 at JetBrains.ReSharper.Shell.Progress.TaskHelper.Run() in c:\TEMP\tmpABD0.tmp\src\Shell\src\Progress\ProgressWindow.cs:line 419 at JetBrains.ReSharper.Shell.Progress.AsyncTaskHelper.ThreadFunc() in c:\TEMP\tmpABD0.tmp\src\Shell\src\Progress\ProgressWindow.cs:line 465 Assemblies in the solution (two projects): First project: Infragistics.Shared.v5.1 Infragistics.Win.Misc.v5.1 Infragistics.Win.UltraWinEditors.v5.1 Infragistics.Win.UltraWinGrid.v5.1 Infragistics.Win.UltraWinMaskedEdit.v5.1 Infragistics.Win.v5.1 Microsoft.VisualBasic mscorlib PureComponents.NicePanel.fw11 System System.Data System.Design System.Drawing System.Runtime.Serialization.Formatters.Soap System.Windows.Forms System.Xml Second project: Infragistics.Shared.v5.1 Infragistics.Win.Misc.v5.1 Infragistics.Win.UltraWinEditors.v5.1 Infragistics.Win.UltraWinGrid.v5.1 Infragistics.Win.UltraWinMaskedEdit.v5.1 Infragistics.Win.v5.1 Microsoft.VisualBasic mscorlib PureComponents.NicePanel.fw11 System System.Data System.Design System.Drawing System.Runtime.Serialization.Formatters.Soap System.Windows.Forms System.Xml Regards