System.Runtime.InteropServices.COMException (0x80040154): [closed]

Answer 1

I was running a C++ COM DLL from a Win Forms C# project on a 64-bit OS. I changed the Win Forms C# project to be x86, re-ran, and it worked. To do this:-

1. Right-click the .NET project, and choose Properties
2. Select the Build tab
3. Set Platform target to x86
4. Recompile, and re-run

Concept of changing bitness from George J's answer