there is currently an issue with the installers on macOS Sierra but it is being worked upon and it is expected to be corrected during the first half of this week.
It should now be possible to install EZXs (or any other product for that matter) using the Product Manager on macOS Sierra. The Product Manager will auto-update when you launch it next, so there is nothing to download from the site for Sierra compatibility in that context.
Note that an upcoming OSX Sierra release seems to address the issue that affects our installers, as found on SDXs and EZXs products DVD, so it’s possible the situation irons itself out for those unable to download products from our servers (through the Product Manager).
