It looks like 2DA's require being encoded as UTF-8 in order for them to work in haks.
Weird - didnt know that.
Only found out because I was working on a Continuous Integration system that was going to generate the 2da for my music hak, and then have it automatically included in a hak which was generated by my Jenkins instance.
The 2da from Jenkins didnt work : The music dropdowns in the area properties would just be totally blank - no music at all.
On looking at the encoding - it was encoded as UTF-BOM whatever that is.
Resaving it via notepad++ as utf-8 then using nwhak to put it back in the hak made it work.
Wonder what part of my system is changing the encoding.
Downloading it from my MVC Web Service to a Linux system, use in erfpacker to generate the hak?