ExtractMethodCodeRefactoringProvider encountered an error and has been disabled.

[JoshVarty]

Version Used: 15.1.26405.1

Steps to Reproduce:

I'm not sure if this is reproducible outside of my solution. :(
Unfortunately it also doesn't seem to reproduce consistently.

1. Comment out code in if-else
2. Lowercase all code within the comment
3. Uncomment it

I've been reproducing it with Ctr+Z and Ctr+Y below:

Stack

System.InvalidOperationException : Unexpected false
   at Roslyn.Utilities.Contract.ThrowIfFalse(Boolean condition,String message)
   at Microsoft.CodeAnalysis.ExtractMethod.ExtractMethodMatrix.GetVariableStyle(Boolean captured,Boolean dataFlowIn,Boolean dataFlowOut,Boolean alwaysAssigned,Boolean variableDeclared,Boolean readInside,Boolean writtenInside,Boolean readOutside,Boolean writtenOutside,Boolean unsafeAddressTaken)
   at Microsoft.CodeAnalysis.ExtractMethod.MethodExtractor.Analyzer.GetVariableStyle(Dictionary`2 symbolMap,ISymbol symbol,SemanticModel model,ITypeSymbol type,Boolean captured,Boolean dataFlowIn,Boolean dataFlowOut,Boolean alwaysAssigned,Boolean variableDeclared,Boolean readInside,Boolean writtenInside,Boolean readOutside,Boolean writtenOutside,Boolean unsafeAddressTaken)
   at Microsoft.CodeAnalysis.ExtractMethod.MethodExtractor.Analyzer.GenerateVariableInfoMap(SemanticModel model,DataFlowAnalysis dataFlowAnalysisData,Dictionary`2 symbolMap)
   at async Microsoft.CodeAnalysis.ExtractMethod.MethodExtractor.Analyzer.AnalyzeAsync(<Unknown Parameters>)
   at async Microsoft.CodeAnalysis.ExtractMethod.MethodExtractor.ExtractMethodAsync(<Unknown Parameters>)
   at async Microsoft.CodeAnalysis.ExtractMethod.AbstractExtractMethodService`3.ExtractMethodAsync[TValidator,TExtractor,TResult](<Unknown Parameters>)
   at async Microsoft.CodeAnalysis.CodeRefactorings.ExtractMethod.ExtractMethodCodeRefactoringProvider.GetCodeActionAsync(<Unknown Parameters>)
   at async Microsoft.CodeAnalysis.CodeRefactorings.ExtractMethod.ExtractMethodCodeRefactoringProvider.ComputeRefactoringsAsync(<Unknown Parameters>)
   at async Microsoft.CodeAnalysis.CodeRefactorings.CodeRefactoringService.GetRefactoringFromProviderAsync(<Unknown Parameters>)
   at Microsoft.VisualStudio.Telemetry.WindowsErrorReporting.WatsonReport.GetClrWatsonExceptionInfo(Exception exceptionObject)

[JoshVarty]

Note also that I'm saving the file in the above gif. I don't know if this is required or not, I haven't been able to find a minimum repro for it yet.

[CyrusNajmabadi]

Likely a dupe of #17165