I've finally figured it out, a year late to the party, but I've figured it out.
The plugin can't parse version 9 rsb files, which is what my old Project Novo files were saved in, it'll open version 8 files perfectly fine.
which can only mean that the plugin I'm using is out of date, strange seeing as it's the one from the DL section, I'd assume that would be the most up to date.