Process terminated. Assertion failed.
awaiterFieldRef.Type.IsObjectType()
   at Microsoft.CodeAnalysis.CSharp.AsyncMethodToStateMachineRewriter.GenerateAwaitForIncompleteTask(LocalSymbol awaiterTemp, BoundAwaitExpressionDebugInfo debugInfo) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\AsyncRewriter\AsyncMethodToStateMachineRewriter.cs:line 536
   at Microsoft.CodeAnalysis.CSharp.AsyncMethodToStateMachineRewriter.VisitAwaitExpression(BoundAwaitExpression node, BoundExpression resultPlace) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\AsyncRewriter\AsyncMethodToStateMachineRewriter.cs:line 380
   at Microsoft.CodeAnalysis.CSharp.AsyncMethodToStateMachineRewriter.VisitExpressionStatement(BoundExpressionStatement node) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\AsyncRewriter\AsyncMethodToStateMachineRewriter.cs:line 324
   at Microsoft.CodeAnalysis.CSharp.BoundExpressionStatement.Accept(BoundTreeVisitor visitor) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Generated\BoundNodes.xml.Generated.cs:line 3705
   at Microsoft.CodeAnalysis.CSharp.BoundTreeVisitor.Visit(BoundNode node) in D:\Code\roslyn\src\Compilers\CSharp\Portable\BoundTree\BoundTreeVisitors.cs:line 151
   at Microsoft.CodeAnalysis.CSharp.BoundTreeRewriterWithStackGuard.Visit(BoundNode node) in D:\Code\roslyn\src\Compilers\CSharp\Portable\BoundTree\BoundTreeRewriter.cs:line 223
   at Microsoft.CodeAnalysis.CSharp.MethodToStateMachineRewriter.Visit(BoundNode node) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\StateMachineRewriter\MethodToStateMachineRewriter.cs:line 519
   at Microsoft.CodeAnalysis.CSharp.BoundTreeRewriter.DoVisitList[T](ImmutableArray`1 list) in D:\Code\roslyn\src\Compilers\CSharp\Portable\BoundTree\BoundTreeRewriter.cs:line 40
   at Microsoft.CodeAnalysis.CSharp.BoundTreeRewriter.VisitList[T](ImmutableArray`1 list) in D:\Code\roslyn\src\Compilers\CSharp\Portable\BoundTree\BoundTreeRewriter.cs:line 29
   at Microsoft.CodeAnalysis.CSharp.BoundTreeToDifferentEnclosingContextRewriter.VisitBlock(BoundBlock node, Boolean removeInstrumentation) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\BoundTreeToDifferentEnclosingContextRewriter.cs:line 109
   at Microsoft.CodeAnalysis.CSharp.MethodToStateMachineRewriter.<>c__DisplayClass48_0.<VisitBlock>b__0() in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\StateMachineRewriter\MethodToStateMachineRewriter.cs:line 532
   at Microsoft.CodeAnalysis.CSharp.MethodToStateMachineRewriter.PossibleIteratorScope(ImmutableArray`1 locals, Func`1 wrapped) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\StateMachineRewriter\MethodToStateMachineRewriter.cs:line 347
   at Microsoft.CodeAnalysis.CSharp.MethodToStateMachineRewriter.VisitBlock(BoundBlock node) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\StateMachineRewriter\MethodToStateMachineRewriter.cs:line 532
   at Microsoft.CodeAnalysis.CSharp.BoundBlock.Accept(BoundTreeVisitor visitor) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Generated\BoundNodes.xml.Generated.cs:line 3345
   at Microsoft.CodeAnalysis.CSharp.BoundTreeVisitor.Visit(BoundNode node) in D:\Code\roslyn\src\Compilers\CSharp\Portable\BoundTree\BoundTreeVisitors.cs:line 151
   at Microsoft.CodeAnalysis.CSharp.BoundTreeRewriterWithStackGuard.Visit(BoundNode node) in D:\Code\roslyn\src\Compilers\CSharp\Portable\BoundTree\BoundTreeRewriter.cs:line 223
   at Microsoft.CodeAnalysis.CSharp.MethodToStateMachineRewriter.Visit(BoundNode node) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\StateMachineRewriter\MethodToStateMachineRewriter.cs:line 519
   at Microsoft.CodeAnalysis.CSharp.BoundTreeRewriter.VisitSequencePoint(BoundSequencePoint node) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Generated\BoundNodes.xml.Generated.cs:line 11384
   at Microsoft.CodeAnalysis.CSharp.BoundSequencePoint.Accept(BoundTreeVisitor visitor) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Generated\BoundNodes.xml.Generated.cs:line 3177
   at Microsoft.CodeAnalysis.CSharp.BoundTreeVisitor.Visit(BoundNode node) in D:\Code\roslyn\src\Compilers\CSharp\Portable\BoundTree\BoundTreeVisitors.cs:line 151
   at Microsoft.CodeAnalysis.CSharp.BoundTreeRewriterWithStackGuard.Visit(BoundNode node) in D:\Code\roslyn\src\Compilers\CSharp\Portable\BoundTree\BoundTreeRewriter.cs:line 223
   at Microsoft.CodeAnalysis.CSharp.MethodToStateMachineRewriter.Visit(BoundNode node) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\StateMachineRewriter\MethodToStateMachineRewriter.cs:line 519
   at Microsoft.CodeAnalysis.CSharp.BoundTreeRewriter.DoVisitList[T](ImmutableArray`1 list) in D:\Code\roslyn\src\Compilers\CSharp\Portable\BoundTree\BoundTreeRewriter.cs:line 40
   at Microsoft.CodeAnalysis.CSharp.BoundTreeRewriter.VisitList[T](ImmutableArray`1 list) in D:\Code\roslyn\src\Compilers\CSharp\Portable\BoundTree\BoundTreeRewriter.cs:line 29
   at Microsoft.CodeAnalysis.CSharp.BoundTreeToDifferentEnclosingContextRewriter.VisitBlock(BoundBlock node, Boolean removeInstrumentation) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\BoundTreeToDifferentEnclosingContextRewriter.cs:line 109
   at Microsoft.CodeAnalysis.CSharp.MethodToStateMachineRewriter.<>c__DisplayClass48_0.<VisitBlock>b__0() in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\StateMachineRewriter\MethodToStateMachineRewriter.cs:line 532
   at Microsoft.CodeAnalysis.CSharp.MethodToStateMachineRewriter.PossibleIteratorScope(ImmutableArray`1 locals, Func`1 wrapped) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\StateMachineRewriter\MethodToStateMachineRewriter.cs:line 305
   at Microsoft.CodeAnalysis.CSharp.MethodToStateMachineRewriter.VisitBlock(BoundBlock node) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\StateMachineRewriter\MethodToStateMachineRewriter.cs:line 532
   at Microsoft.CodeAnalysis.CSharp.BoundBlock.Accept(BoundTreeVisitor visitor) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Generated\BoundNodes.xml.Generated.cs:line 3345
   at Microsoft.CodeAnalysis.CSharp.BoundTreeVisitor.Visit(BoundNode node) in D:\Code\roslyn\src\Compilers\CSharp\Portable\BoundTree\BoundTreeVisitors.cs:line 151
   at Microsoft.CodeAnalysis.CSharp.BoundTreeRewriterWithStackGuard.Visit(BoundNode node) in D:\Code\roslyn\src\Compilers\CSharp\Portable\BoundTree\BoundTreeRewriter.cs:line 223
   at Microsoft.CodeAnalysis.CSharp.MethodToStateMachineRewriter.Visit(BoundNode node) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\StateMachineRewriter\MethodToStateMachineRewriter.cs:line 519
   at Microsoft.CodeAnalysis.CSharp.MethodToStateMachineRewriter.VisitTryStatement(BoundTryStatement node) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\StateMachineRewriter\MethodToStateMachineRewriter.cs:line 735
   at Microsoft.CodeAnalysis.CSharp.BoundTryStatement.Accept(BoundTreeVisitor visitor) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Generated\BoundNodes.xml.Generated.cs:line 4266
   at Microsoft.CodeAnalysis.CSharp.BoundTreeVisitor.Visit(BoundNode node) in D:\Code\roslyn\src\Compilers\CSharp\Portable\BoundTree\BoundTreeVisitors.cs:line 151
   at Microsoft.CodeAnalysis.CSharp.BoundTreeRewriterWithStackGuard.Visit(BoundNode node) in D:\Code\roslyn\src\Compilers\CSharp\Portable\BoundTree\BoundTreeRewriter.cs:line 223
   at Microsoft.CodeAnalysis.CSharp.MethodToStateMachineRewriter.Visit(BoundNode node) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\StateMachineRewriter\MethodToStateMachineRewriter.cs:line 519
   at Microsoft.CodeAnalysis.CSharp.BoundTreeRewriter.DoVisitList[T](ImmutableArray`1 list) in D:\Code\roslyn\src\Compilers\CSharp\Portable\BoundTree\BoundTreeRewriter.cs:line 40
   at Microsoft.CodeAnalysis.CSharp.BoundTreeRewriter.VisitList[T](ImmutableArray`1 list) in D:\Code\roslyn\src\Compilers\CSharp\Portable\BoundTree\BoundTreeRewriter.cs:line 29
   at Microsoft.CodeAnalysis.CSharp.BoundTreeToDifferentEnclosingContextRewriter.VisitBlock(BoundBlock node, Boolean removeInstrumentation) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\BoundTreeToDifferentEnclosingContextRewriter.cs:line 109
   at Microsoft.CodeAnalysis.CSharp.MethodToStateMachineRewriter.<>c__DisplayClass48_0.<VisitBlock>b__0() in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\StateMachineRewriter\MethodToStateMachineRewriter.cs:line 532
   at Microsoft.CodeAnalysis.CSharp.MethodToStateMachineRewriter.PossibleIteratorScope(ImmutableArray`1 locals, Func`1 wrapped) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\StateMachineRewriter\MethodToStateMachineRewriter.cs:line 347
   at Microsoft.CodeAnalysis.CSharp.MethodToStateMachineRewriter.VisitBlock(BoundBlock node) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\StateMachineRewriter\MethodToStateMachineRewriter.cs:line 532
   at Microsoft.CodeAnalysis.CSharp.BoundBlock.Accept(BoundTreeVisitor visitor) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Generated\BoundNodes.xml.Generated.cs:line 3345
   at Microsoft.CodeAnalysis.CSharp.BoundTreeVisitor.Visit(BoundNode node) in D:\Code\roslyn\src\Compilers\CSharp\Portable\BoundTree\BoundTreeVisitors.cs:line 151
   at Microsoft.CodeAnalysis.CSharp.BoundTreeRewriterWithStackGuard.Visit(BoundNode node) in D:\Code\roslyn\src\Compilers\CSharp\Portable\BoundTree\BoundTreeRewriter.cs:line 223
   at Microsoft.CodeAnalysis.CSharp.MethodToStateMachineRewriter.Visit(BoundNode node) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\StateMachineRewriter\MethodToStateMachineRewriter.cs:line 519
   at Microsoft.CodeAnalysis.CSharp.AsyncMethodToStateMachineRewriter.VisitBody(BoundStatement body) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\AsyncRewriter\AsyncMethodToStateMachineRewriter.cs:line 311
   at Microsoft.CodeAnalysis.CSharp.AsyncMethodToStateMachineRewriter.GenerateMoveNext(BoundStatement body, MethodSymbol moveNextMethod) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\AsyncRewriter\AsyncMethodToStateMachineRewriter.cs:line 144
   at Microsoft.CodeAnalysis.CSharp.AsyncRewriter.GenerateMoveNext(SynthesizedImplementationMethod moveNextMethod) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\AsyncRewriter\AsyncRewriter.cs:line 296
   at Microsoft.CodeAnalysis.CSharp.AsyncRewriter.GenerateMethodImplementations() in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\AsyncRewriter\AsyncRewriter.cs:line 160
   at Microsoft.CodeAnalysis.CSharp.StateMachineRewriter.Rewrite() in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\StateMachineRewriter\StateMachineRewriter.cs:line 130
   at Microsoft.CodeAnalysis.CSharp.AsyncRewriter.Rewrite(BoundStatement bodyWithAwaitLifted, MethodSymbol method, Int32 methodOrdinal, ArrayBuilder`1 stateMachineStateDebugInfoBuilder, VariableSlotAllocator slotAllocatorOpt, TypeCompilationState compilationState, BindingDiagnosticBag diagnostics, AsyncStateMachine& stateMachineType) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Lowering\AsyncRewriter\AsyncRewriter.cs:line 90
   at Microsoft.CodeAnalysis.CSharp.MethodCompiler.LowerBodyOrInitializer(MethodSymbol method, SourceExtensionImplementationMethodSymbol extensionImplementationMethod, Int32 methodOrdinal, BoundStatement body, SynthesizedSubmissionFields previousSubmissionFields, TypeCompilationState compilationState, MethodInstrumentation instrumentation, DebugDocumentProvider debugDocumentProvider, ImmutableArray`1& codeCoverageSpans, BindingDiagnosticBag diagnostics, VariableSlotAllocator& lazyVariableSlotAllocator, ArrayBuilder`1 lambdaDebugInfoBuilder, ArrayBuilder`1 lambdaRuntimeRudeEditsBuilder, ArrayBuilder`1 closureDebugInfoBuilder, ArrayBuilder`1 stateMachineStateDebugInfoBuilder, StateMachineTypeSymbol& stateMachineTypeOpt) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Compiler\MethodCompiler.cs:line 1609
   at Microsoft.CodeAnalysis.CSharp.MethodCompiler.CompileMethod(MethodSymbol methodSymbol, Int32 methodOrdinal, ProcessedFieldInitializers& processedInitializers, SynthesizedSubmissionFields previousSubmissionFields, TypeCompilationState compilationState) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Compiler\MethodCompiler.cs:line 1224
   at Microsoft.CodeAnalysis.CSharp.MethodCompiler.CompileNamedType(NamedTypeSymbol containingType) in D:\Code\roslyn\src\Compilers\CSharp\Portable\Compiler\MethodCompiler.cs:line 561
   at Microsoft.CodeAnalysis.CSharp.MethodCompiler.<>c__DisplayClass25_0.<CompileNamedTypeAsync>b__0() in D:\Code\roslyn\src\Compilers\CSharp\Portable\Compiler\MethodCompiler.cs:line 446
   at Roslyn.Utilities.UICultureUtilities.<>c__DisplayClass5_0.<WithCurrentUICulture>b__0() in D:\Code\roslyn\src\Compilers\Core\Portable\InternalUtilities\UICultureUtilities.cs:line 139
   at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)
   at System.Threading.ThreadPoolWorkQueue.Dispatch()
   at System.Threading.PortableThreadPool.WorkerThread.WorkerThreadStart()