Maybe something you removed really was needed?
Or perhaps your design is perfect, but the soldering or other physical construction has a problem?
Please understand we can't see your hardware or schematic, and we have almost no information other than a screenshot of an error you would get if nothing was connected you PC. The best anyone can do is blind guesswork. But there isn't even much info to try guessing.
Yeah, I think I asked questions so vaguely... I attached the schematic we are using for everyone's reference.
If you see something, please let me know.
I appreciate you all for being so responsive!