System.InvalidCastException : Unable to cast object of type 'Microsoft.CodeAnalysis.CSharp.Symbols.Metadata.PE.PEAssemblySymbol' to type 'Microsoft.CodeAnalysis.CSharp.Symbols.SourceAssemblySymbol'.
   at Microsoft.CodeAnalysis.CSharp.DefiniteAssignmentPass..ctor(CSharpCompilation compilation,Symbol member,BoundNode node,EmptyStructTypeCache emptyStructs,Boolean trackUnassignments,HashSet`1 initiallyAssignedVariables)
   at Microsoft.CodeAnalysis.CSharp.UnassignedVariablesWalker.Analyze(CSharpCompilation compilation,Symbol member,BoundNode node,Boolean convertInsufficientExecutionStackExceptionToCancelledByStackGuardException)
   at Microsoft.CodeAnalysis.CSharp.CSharpDataFlowAnalysis.get_UnassignedVariables()
   at Microsoft.CodeAnalysis.CSharp.CSharpDataFlowAnalysis.get_DataFlowsIn()
   at Microsoft.CodeAnalysis.CSharp.CSharpDataFlowAnalysis.get_Succeeded()
   at Microsoft.CodeAnalysis.CSharp.CSharpDataFlowAnalysis.AnalyzeReadWrite()
   at Microsoft.CodeAnalysis.CSharp.CSharpDataFlowAnalysis.get_Captured()
   at Microsoft.CodeAnalysis.ExtractMethod.MethodExtractor.Analyzer.GenerateVariableInfoMap(Boolean bestEffort,SemanticModel model,DataFlowAnalysis dataFlowAnalysisData,Dictionary`2 symbolMap,IDictionary`2& variableInfoMap,List`1& failedVariables)
   at async Microsoft.CodeAnalysis.ExtractMethod.MethodExtractor.Analyzer.AnalyzeAsync(<Unknown Parameters>)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at async Microsoft.CodeAnalysis.ExtractMethod.MethodExtractor.ExtractMethodAsync(<Unknown Parameters>)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at async Microsoft.CodeAnalysis.ExtractMethod.AbstractExtractMethodService`3.ExtractMethodAsync[TValidator,TExtractor,TResult](<Unknown Parameters>)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at async Microsoft.CodeAnalysis.CodeRefactorings.ExtractMethod.ExtractMethodCodeRefactoringProvider.ExtractMethodAsync(<Unknown Parameters>)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at async Microsoft.CodeAnalysis.CodeRefactorings.ExtractMethod.ExtractMethodCodeRefactoringProvider.GetCodeActionsAsync(<Unknown Parameters>)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at async Microsoft.CodeAnalysis.CodeRefactorings.ExtractMethod.ExtractMethodCodeRefactoringProvider.ComputeRefactoringsAsync(<Unknown Parameters>)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at async Microsoft.CodeAnalysis.CodeRefactorings.CodeRefactoringService.GetRefactoringFromProviderAsync(<Unknown Parameters>)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at Microsoft.VisualStudio.Telemetry.WindowsErrorReporting.WatsonReport.GetClrWatsonExceptionInfo(Exception exceptionObject)