There was nothing wrong with my Formula. It was directly tied to WHEN and HOW I saved the replacement lookup file. Even if I thought I was saving over an existing file, for some reason, Revit wasn't seeing that. So it wasn't updating. Once I got all of the information that I needed into my lookup file, I saved it as a completely new name, then added the new Lookup File Name to my Family Types, and lastly, added the formula. Then it worked!
I am going crazy getting this to work. I am trying lookup tables and I keep getting invalid input. I have gone down to a simple test...
The csv at the top "Motor.csv" only has 2 columns... first column which is the driver and 2nd column to be filled in. Attached is a screenshot of the family. I just want this to be number values but that wasn't working so I tried changing it to lengths and still nothing.
Tried doing a save as with a different name and still no go. Tried closing and re-opening revit after changes and still no.