Steps to reproduce

1. Open file Game.dll from Cities Skylines II version 1.2.5f1.
2. Expand to Game.Debug.DebugSystem.
3. Click on Game.Debug.DebugSystem.BuildRenderingDebugUI.

Error message shown

Error decompiling @06004D3C Game.Debug.DebugSystem.BuildRenderingDebugUI
in assembly "C:\Program Files (x86)\Steam\steamapps\common\Cities Skylines II\Cities2_Data\Managed\Game.dll"
---> System.NullReferenceException: Object reference not set to an instance of an object.
at ICSharpCode.Decompiler.CSharp.CallBuilder.DisambiguateDelegateReference(IMethod method, IMethod invokeMethod, ExpectedTargetDetails expectedTargetDetails, ILInstruction thisArg) in CallBuilder.cs:line 1859
at ICSharpCode.Decompiler.CSharp.CallBuilder.BuildDelegateReference(IMethod method, IMethod invokeMethod, ExpectedTargetDetails expectedTargetDetails, ILInstruction thisArg) in CallBuilder.cs:line 1832
at ICSharpCode.Decompiler.CSharp.CallBuilder.HandleDelegateConstruction(CallInstruction inst) in CallBuilder.cs:line 1766
at ICSharpCode.Decompiler.CSharp.CallBuilder.Build(CallInstruction inst, IType typeHint) in CallBuilder.cs:line 195
at ICSharpCode.Decompiler.CSharp.ExpressionBuilder.VisitNewObj(NewObj inst, TranslationContext context) in ExpressionBuilder.cs:line 440
at ICSharpCode.Decompiler.CSharp.ExpressionBuilder.Translate(ILInstruction inst, IType typeHint) in ExpressionBuilder.cs:line 163
at ICSharpCode.Decompiler.CSharp.ExpressionBuilder.BuildArrayInitializerExpression(Block block, InitializedObjectResolveResult initObjRR) in ExpressionBuilder.cs:line 3460
at ICSharpCode.Decompiler.CSharp.ExpressionBuilder.TranslateObjectAndCollectionInitializer(Block block) in ExpressionBuilder.cs:line 3385
at ICSharpCode.Decompiler.CSharp.ExpressionBuilder.VisitBlock(Block block, TranslationContext context) in ExpressionBuilder.cs:line 3278
at ICSharpCode.Decompiler.CSharp.ExpressionBuilder.Translate(ILInstruction inst, IType typeHint) in ExpressionBuilder.cs:line 163
at ICSharpCode.Decompiler.CSharp.CallBuilder.BuildArgumentList(ExpectedTargetDetails expectedTargetDetails, ResolveResult target, IMethod method, Int32 firstParamIndex, IReadOnlyList1 callArguments, IReadOnlyList1 argumentToParameterMap) in CallBuilder.cs:line 877
at ICSharpCode.Decompiler.CSharp.ExpressionBuilder.BuildArrayInitializerExpression(Block block, InitializedObjectResolveResult initObjRR) in ExpressionBuilder.cs:line 3391
at ICSharpCode.Decompiler.CSharp.ExpressionBuilder.TranslateObjectAndCollectionInitializer(Block block) in ExpressionBuilder.cs:line 3385
at ICSharpCode.Decompiler.CSharp.ExpressionBuilder.VisitBlock(Block block, TranslationContext context) in ExpressionBuilder.cs:line 3278
at ICSharpCode.Decompiler.CSharp.ExpressionBuilder.Translate(ILInstruction inst, IType typeHint) in ExpressionBuilder.cs:line 163
at ICSharpCode.Decompiler.CSharp.ExpressionBuilder.VisitStLoc(StLoc inst, TranslationContext context) in ExpressionBuilder.cs:line 749
at ICSharpCode.Decompiler.CSharp.ExpressionBuilder.Translate(ILInstruction inst, IType typeHint) in ExpressionBuilder.cs:line 163
at ICSharpCode.Decompiler.CSharp.StatementBuilder.VisitStLoc(StLoc inst) in StatementBuilder.cs:line 116
at ICSharpCode.Decompiler.CSharp.StatementBuilder.Convert(ILInstruction inst) in StatementBuilder.cs:line 80
at ICSharpCode.Decompiler.CSharp.StatementBuilder.ConvertBlockContainer(BlockStatement blockStatement, BlockContainer container, IEnumerable1 blocks, Boolean isLoop) in StatementBuilder.cs:line 1443 at ICSharpCode.Decompiler.CSharp.StatementBuilder.ConvertBlockContainer(BlockContainer container, Boolean isLoop) in StatementBuilder.cs:line 1347 at ICSharpCode.Decompiler.CSharp.StatementBuilder.VisitBlockContainer(BlockContainer container) in StatementBuilder.cs:line 1233 at ICSharpCode.Decompiler.CSharp.StatementBuilder.Convert(ILInstruction inst) in StatementBuilder.cs:line 80 at ICSharpCode.Decompiler.CSharp.CSharpDecompiler.DecompileBody(IMethod method, EntityDeclaration entityDecl, DecompileRun decompileRun, ITypeResolveContext decompilationContext) in CSharpDecompiler.cs:line 1780 -- continuing with outer exception (ICSharpCode.Decompiler.DecompilerException) -- at ICSharpCode.Decompiler.CSharp.CSharpDecompiler.DecompileBody(IMethod method, EntityDeclaration entityDecl, DecompileRun decompileRun, ITypeResolveContext decompilationContext) in CSharpDecompiler.cs:line 1795 at ICSharpCode.Decompiler.CSharp.CSharpDecompiler.DoDecompile(IMethod method, DecompileRun decompileRun, ITypeResolveContext decompilationContext) in CSharpDecompiler.cs:line 1644 at ICSharpCode.Decompiler.CSharp.CSharpDecompiler.Decompile(IEnumerable1 definitions) in CSharpDecompiler.cs:line 1050
at ICSharpCode.Decompiler.CSharp.CSharpDecompiler.Decompile(EntityHandle[] definitions) in CSharpDecompiler.cs:line 1010
at ICSharpCode.ILSpy.CSharpLanguage.DecompileMethod(IMethod method, ITextOutput output, DecompilationOptions options) in offset 216
at ICSharpCode.ILSpy.TreeNodes.MethodTreeNode.Decompile(Language language, ITextOutput output, DecompilationOptions options) in offset 0
at ICSharpCode.ILSpy.TextView.DecompilerTextView.DecompileNodes(DecompilationContext context, ITextOutput textOutput) in offset 103
at ICSharpCode.ILSpy.TextView.DecompilerTextView.<>c__DisplayClass58_0.b__0() in offset 18

Details

• VS extension
• ILSpy version 9.0.0.7889+e94eb917395e50c74ea363a79df3514538989daa
• Error occurs only when C# 7.0 or later is selected.