what

using System.Reflection;

public interface IMyInterface
{
    void MyFunction();
}

public struct MyStruct : IMyInterface
{
    public void MyFunction() => Console.WriteLine("Hello World!");
}

public unsafe class Program
{
    const int TestMode = 1;
    public static void Main()
    {
        MyStruct instance = default;
        MyStruct* ptr = &instance;
        MethodInfo method = typeof(MyStruct).GetMethod("MyFunction");
        delegate*<void*, void> func1 = (delegate*<void*, void>)method.MethodHandle.GetFunctionPointer();

        switch (TestMode)
        {
            case 1:
                func1(ptr); //System.ExecutionEngineException: 'Exception of type 'System.ExecutionEngineException' was thrown.'
                break;
            case 2:
                func1((void*)1); //System.ExecutionEngineException: 'Exception of type 'System.ExecutionEngineException' was thrown.'
                break;
            case 3:
                func1((void*)0); //no error
                func1(ptr); //no error
                break;
        }
    }
}