I am having difficulty pointing a part to a custom .csv file for the lookup table. I copy a standard .csv file, rename it, and then edit it through excel. When I point the family at my new table (which is located in the same directory as the standard .csv files) I get the "Invalid Formula" error. The only thing that seems to work is if I don't rename the file, and don't add custom parameters. If I just change the numerical values for any given parameter, then it works fine. Do I have to use a specific program to make custom csv files rather than excel and notepad?