Looking a little more at the release notes it appears most users, both on Steam and via CivFanatics downloads, are using version 3.14.
Thalassicus drafted the 3.16 version after I had made a minor release, 3.15.1, around the middle of April. In it he proposed to do some final testing over the weekend and release a new Steam version in addition to the GitHub one. I can only assume this was around the time RL issues took priority with him and those releases never actually took place.
As I mentioned earlier, as a collaborator, when I looked at the release page I saw the draft copy of that release and just assumed it was also seen by all, and hence the latest version could be downloaded. Apparently not.
The next version I release, if you haven't been keeping up with all that is happening here, will be more than likely the last for some time. I will be shifting my attention to the new DLL based mod, Community Balance Project, and will only visit this sub-forum infrequently.
I have left comments on the Steam Community pages to look either here or the GitHub page for help and I will continue to help ALL users of CEP into the future. Only I will limit the changes to the mod to major bugfixes not feature change.
Again, apologies for the error with the download.