Well, sloppy copy&paste on your part. Start by removing your line break and check for other such stuff like unnecessary spaces. Invisible characters count in code. also be aware that running CS6 on current versions of OSX may cause further errors due to Unicode issues. You may have to rename stuff to not include spaces and special characters.
Right now I'm planning on leaving as many of them as ai layers as possible and converting things to shape layers only when necessary (if I need to make masks/gradients that aren't an ai file already).
That is correct. People simply completely misunderstand the intent of this function and ignore the fact that you could work just fine with native AI files for eons. When working with effects it's a moot point, anyway - even shape layers get rasterized then.
The thing is though, I didn't copy and paste or type ANY expressions whatsoever. The above expression appears out of nowhere whenever I make it so I can add an expression to the property of a puppet pin position, but before inputting any expression myself. I'm not sure whether it's generated for a reason or not. It looks like it's a path/address for the puppet pin position?
I've been wondering about that for a while about the ai layers. I remember reading on the Adobe website that of all the ways the puppet pin makes an outline around objects, using ai layers wasn't one of them. Plus that means less layers to have to deal with since I don't have to make shape layer copies, so that's nice.
I really just need to spend more time learning about After Effects expression system and how to implement it and hopefully it shouldn't even matter that this erroneous expression is showing up.
Thanks for taking the time to reply and info!