This is the Tywom race created by Derek shortly after version 1.0 of the game was released. I downloaded it and have had it available in my games since then.
After not playing for a while, I decided to start a new game today. I noticed a number next to the icon for the workshop. I found that it meant that an update was available for something I was subscribed to. I told it to update, which it seemed to do. I didn't know what had been updated, but I eventually figured out that it was the Tywom, and the update was 12 days ago. I still didn't know what had been done, so I decided to start a new game and check the Tywom to see if I could tell what had changed.
The Tywom weren't available.
I couldn't find them in the list of races I could play as. I couldn't find them in the list of races that I could manually add to the game. With the 18 races that come with the game and the 15 I have subscribed to, I should be able to have 33 total races in a game. The most I could get was 32.
I checked the factions directory in my GalCiv4 directory and found the files there with today's date. I tried many combinations of deleting the faction, subscribing to the faction, exiting and restarting GalCiv4, but they never appeared.
I hope someone can check to see what happened.
I found a copy of the original files for the Tywom on another computer. I copied them into the factions directory on my current computer and found that the Tywom appear in the list of races just like they did before the update. There is definitely something wrong with the updated version.
In case the original files are needed, a folder containing them is available here.