D'oh. Should included that info. Sorry.
OS: Ubuntu 16.04 Geany 1.27 geanypy installed through the repository / `geany-plugin-py` package
There was no error message generated that I saw, nothing was outputted to Debug Messages. I'm guessing it crashed before it outputted anything. Running Geany from the command line outputted "Segmentation Fault" to the terminal when it crashed.