It's an Adobe Acrobat file. Acrobat Reader can be buggy at times, so you might want to reinstall it.
The language might not seem familiar to North American eyes, but when you look at it in context, it makes sense. Australian states, Victoria and New South Wales in particular, publish some OUTSTANDING planning-related how-to guides. Yanks and Canucks shouldn't dismiss them only because they have a jolly Aussie accent.