dnlib.DotNet.Writer.ModuleWriterException

[CatLover248]

Hello!

I am having some issues. I am writing to a cilBody then merging the il. But when I try to write it with module.Write() I get an error.

var cilBody = method.Body;
method.Body.Instructions.Clear();
cilBody.Instructions.Add(new Instruction......
method.Body.UpdateInstructionOffsets();
method.Body.KeepOldMaxStack = true;

dnlib.DotNet.Writer.ModuleWriterException
HResult=0x80131500
Message=Instruction is null. Error occurred after metadata event BeginWriteMethodBodies during writing method 'System.Void ConsoleAppTestForObfuscation.Program::Main(System.String[])' (0x06000001).
Source=dnlib
StackTrace:
at dnlib.DotNet.DummyLogger.Log(Object sender, LoggerEvent loggerEvent, String format, Object[] args)
at dnlib.DotNet.Writer.ModuleWriterBase.dnlib.DotNet.ILogger.Log(Object sender, LoggerEvent loggerEvent, String format, Object[] args)
at dnlib.DotNet.Writer.Metadata.Error(String message, Object[] args)
at dnlib.DotNet.Writer.Metadata.dnlib.DotNet.Writer.IWriterError.Error(String message)
at dnlib.DotNet.Writer.MethodBodyWriter.ErrorImpl(String message)
at dnlib.DotNet.Writer.MethodBodyWriterBase.Error(String message)
at dnlib.DotNet.Writer.MethodBodyWriterBase.GetOffset(Instruction instr)
at dnlib.DotNet.Writer.MethodBodyWriterBase.WriteShortInlineBrTarget(ArrayWriter& writer, Instruction instr)
at dnlib.DotNet.Writer.MethodBodyWriterBase.WriteOperand(ArrayWriter& writer, Instruction instr)
at dnlib.DotNet.Writer.MethodBodyWriterBase.WriteInstruction(ArrayWriter& writer, Instruction instr)
at dnlib.DotNet.Writer.MethodBodyWriterBase.WriteInstructions(ArrayWriter& writer)
at dnlib.DotNet.Writer.MethodBodyWriter.WriteFatHeader()
at dnlib.DotNet.Writer.MethodBodyWriter.Write()
at dnlib.DotNet.Writer.Metadata.WriteMethodBodies()
at dnlib.DotNet.Writer.Metadata.Create()
at dnlib.DotNet.Writer.Metadata.CreateTables()
at dnlib.DotNet.Writer.ModuleWriter.WriteImpl()
at dnlib.DotNet.Writer.ModuleWriterBase.Write(Stream dest)
at dnlib.DotNet.Writer.ModuleWriterBase.Write(String fileName)
at dnlib.DotNet.ModuleDef.Write(String filename, ModuleWriterOptions options)
at dnlib.DotNet.ModuleDef.Write(String filename)
at MeteorObfuscation.Meteor.MeteorObfuscation.init(String path) in C:\Users\hampter\source\repos\MeteorObfuscation\MeteorObfuscation\Meteor\MeteorObfuscation.cs:line 37
at MeteorObfuscation.Form1.button1_Click(Object sender, EventArgs e) in C:\Users\hampter\source\repos\MeteorObfuscation\MeteorObfuscation\Form1.cs:line 27
at System.Windows.Forms.Button.OnClick(EventArgs e)
at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(HWND hWnd, MessageId msg, WPARAM wparam, LPARAM lparam)

[wtfsck]

The message says the instruction is null so check which instruction is null. Also check exception handlers and other places that could have instruction references.

[CatLover248]

Thank you for your help!

Ive been able to identify the null instruction by checking if the individual instructions are null.