The offer file for 1-Aug-2016 is missing from ftp://ftp.emi.ea.govt.nz/Datasets/Wholesale/Bids_and_offers/Offers/2016/201608/
Hey David - thanks for letting us know. The 1 August file is now there.
We recently upgraded SQL Server versions and a bunch of packages required some tweaking to make them work. While the guys did the upgrade on the development environment first, I guess one or two things slipped through the cracks. Be sure to let us know if you find anything else amiss.