How do I create a real-time Excel automation add-in in C# using RtdServer?

Question

I was tasked with writing a real-time Excel automation add-in in C# using RtdServer for work. I relied heavily on the knowledge that I came across in Stack Overflow. I hav

Answer 1

Following the previous two answers for the RTD server worked for me. However I ran into an issue when on an x64 machine running Excel x64. In my case, until I switched the "target platform" of the project to x64, Excel always showed #N/A.