While trying to extract method, got this exception from the rename phase. Dump at rchande\dumps\nulltextbuffer.dmp

Microsoft.CodeAnalysis.Workspaces.dll!Roslyn.Utilities.Contract.ThrowIfNull<System.__Canon>(System.__Canon value, string message)   Unknown

Microsoft.CodeAnalysis.EditorFeatures.dll!Microsoft.CodeAnalysis.Editor.Implementation.InlineRename.InlineRenameSession.InitializeOpenBuffers(Microsoft.VisualStudio.Text.SnapshotSpan triggerSpan) Line 175 C#
Microsoft.CodeAnalysis.EditorFeatures.dll!Microsoft.CodeAnalysis.Editor.Implementation.InlineRename.InlineRenameSession.InlineRenameSession(Microsoft.CodeAnalysis.Editor.Implementation.InlineRename.InlineRenameService renameService, Microsoft.CodeAnalysis.Workspace workspace, Microsoft.VisualStudio.Text.SnapshotSpan triggerSpan, Microsoft.CodeAnalysis.Editor.IInlineRenameInfo renameInfo, Microsoft.CodeAnalysis.Editor.Host.IWaitIndicator waitIndicator, Microsoft.CodeAnalysis.Editor.ITextBufferAssociatedViewService textBufferAssociatedViewService, Microsoft.VisualStudio.Text.ITextBufferFactoryService textBufferFactoryService, System.Collections.Generic.IEnumerable<Microsoft.CodeAnalysis.Editor.IRefactorNotifyService> refactorNotifyServices, Microsoft.CodeAnalysis.Shared.TestHooks.IAsynchronousOperationListener asyncListener) Line 140 C#
Microsoft.CodeAnalysis.EditorFeatures.dll!Microsoft.CodeAnalysis.Editor.Implementation.InlineRename.InlineRenameService.StartInlineSession(Microsoft.CodeAnalysis.Document document, Microsoft.CodeAnalysis.Text.TextSpan textSpan, System.Threading.CancellationToken cancellationToken) Line 62 C#
Microsoft.CodeAnalysis.EditorFeatures.dll!Microsoft.CodeAnalysis.Editor.Implementation.ExtractMethod.AbstractExtractMethodCommandHandler.Execute(Microsoft.VisualStudio.Text.ITextBuffer textBuffer, Microsoft.VisualStudio.Text.Editor.ITextView view, System.Threading.CancellationToken cancellationToken) Line 174 C#
Microsoft.CodeAnalysis.EditorFeatures.dll!Microsoft.CodeAnalysis.Editor.Implementation.ExtractMethod.AbstractExtractMethodCommandHandler.ExecuteCommand.AnonymousMethod__0(Microsoft.CodeAnalysis.Editor.Host.IWaitContext waitContext) Line 104 C#
Microsoft.VisualStudio.LanguageServices.dll!Microsoft.VisualStudio.LanguageServices.Implementation.Utilities.VisualStudioWaitIndicator.Wait(string title, string message, bool allowCancel, System.Action<Microsoft.CodeAnalysis.Editor.Host.IWaitContext> action) Unknown
Microsoft.CodeAnalysis.EditorFeatures.dll!Microsoft.CodeAnalysis.Editor.Implementation.ExtractMethod.AbstractExtractMethodCommandHandler.ExecuteCommand(Microsoft.CodeAnalysis.Editor.Commands.ExtractMethodCommandArgs args, System.Action nextHandler) Line 107 C#
Microsoft.CodeAnalysis.EditorFeatures.dll!Microsoft.CodeAnalysis.Editor.Implementation.Commands.CommandHandlerService.ExecuteHandlers<Microsoft.CodeAnalysis.Editor.Commands.ExtractMethodCommandArgs>(System.Collections.Generic.IList<Microsoft.CodeAnalysis.Editor.ICommandHandler<Microsoft.CodeAnalysis.Editor.Commands.ExtractMethodCommandArgs>> commandHandlers, Microsoft.CodeAnalysis.Editor.Commands.ExtractMethodCommandArgs args, System.Action lastHandler) Line 104 C#
Microsoft.CodeAnalysis.EditorFeatures.dll!Microsoft.CodeAnalysis.Editor.Implementation.Commands.CommandHandlerService.Execute<Microsoft.CodeAnalysis.Editor.Commands.ExtractMethodCommandArgs>(Microsoft.VisualStudio.Utilities.IContentType contentType, Microsoft.CodeAnalysis.Editor.Commands.ExtractMethodCommandArgs args, System.Action lastHandler) Line 71 C#
Microsoft.VisualStudio.LanguageServices.dll!Microsoft.VisualStudio.LanguageServices.Implementation.AbstractOleCommandTarget.ExecuteExtractMethod(Microsoft.VisualStudio.Text.ITextBuffer subjectBuffer, Microsoft.VisualStudio.Utilities.IContentType contentType, System.Action executeNextCommandTarget) Unknown
Microsoft.VisualStudio.LanguageServices.dll!Microsoft.VisualStudio.LanguageServices.Implementation.AbstractOleCommandTarget.ExecuteVisualStudio2000(ref System.Guid pguidCmdGroup, uint commandId, uint executeInformation, System.IntPtr pvaIn, System.IntPtr pvaOut, Microsoft.VisualStudio.Text.ITextBuffer subjectBuffer, Microsoft.VisualStudio.Utilities.IContentType contentType) Unknown
Microsoft.VisualStudio.LanguageServices.dll!Microsoft.VisualStudio.LanguageServices.Implementation.AbstractOleCommandTarget.Exec(ref System.Guid pguidCmdGroup, uint commandId, uint executeInformation, System.IntPtr pvaIn, System.IntPtr pvaOut) Unknown
Microsoft.VisualStudio.Editor.Implementation.dll!Microsoft.VisualStudio.Editor.Implementation.CommandChainNode.InnerExec(ref System.Guid pguidCmdGroup, uint nCmdID, uint nCmdexecopt, System.IntPtr pvaIn, System.IntPtr pvaOut) Unknown
Microsoft.VisualStudio.Editor.Implementation.dll!Microsoft.VisualStudio.Editor.Implementation.SimpleTextViewWindow.Exec(ref System.Guid pguidCmdGroup, uint nCmdID, uint nCmdexecopt, System.IntPtr pvaIn, System.IntPtr pvaOut) Unknown
Microsoft.VisualStudio.Editor.Implementation.dll!Microsoft.VisualStudio.Editor.Implementation.CompoundTextViewWindow.Exec(ref System.Guid pguidCmdGroup, uint nCmdID, uint nCmdexecopt, System.IntPtr pvaIn, System.IntPtr pvaOut) Unknown
Microsoft.VisualStudio.Platform.WindowManagement.dll!Microsoft.VisualStudio.Platform.WindowManagement.DocumentObjectSite.Exec(ref System.Guid pguidCmdGroup, uint nCmdID, uint nCmdexecopt, System.IntPtr pvaIn, System.IntPtr pvaOut) Unknown
Microsoft.VisualStudio.Platform.WindowManagement.dll!Microsoft.VisualStudio.Platform.WindowManagement.WindowFrame.Exec(ref System.Guid pguidCmdGroup, uint nCmdID, uint nCmdexecopt, System.IntPtr pvaIn, System.IntPtr pvaOut) Unknown