If you have a large .zip restore (anything over 1GB) the default zipping utility on your machine may fail and produce errors. We recommend using the following:
For PC: Use the unzipping tool that comes bundled with the Backblaze Downloader.
For Mac: After downloading with the Backblaze Downloader (bundled with the Backblaze app on Macs) use Apple's built in Archive Utility primarily. Alternatives are Stuffit Expander (http://www.stuffit.com/) or The Unarchiver (http://wakaba.c3.cx/s/apps/unarchiver.html)
You can see a video on how to use the downloader for the PC here:
If the video is blurry, please raise the quality.