For anybody having this same issue, it turns out the version of the file is incorrect.
how can this be?
Well it turns out my ISP (Optus Australia) was caching the file and it was the wrong version.
After working with the firewater dev Beaups we worked out the file had the wrong md5 checksum.
to get around this, try download it using mobile data or another network.
Once i got the same file through another link (bypassing ISP cache) it worked as expected.
Hope that helps somebody.