Trying to add a tertiary ability
 

I'm trying to add a tertiary ability field to a version of the 3.5 Warlock where I could type in the ability name and description. I got the new ability to show up in the class tab, but when I click on it, it tells me 'Nothing to choose from!' How do I fix this, and how can I make archetypes that replace abilities?

I'm not 100% sure on what you're trying to accomplish, but it sounds like you used the "item selection" section on custom abilities, when what you want is the "Allow User Text?" box to be checked under the next section down.

As for replacing abilities on archetypes, can you be a little more specific on what you want? Do you mean you want to replace Cass Specials or do you want to use a different list of Custom Abilities?