I am unable to build the Stellar Forge - it is not in my list of available improvements to build.  Here are the steps that I am following:

1. Launch TA

2. Pick Arcean race (I have tried custom with the Arcean tree selected as well)

3. Make certain that a Glorious History is included in the package then start the game

4. Once the game is started, double check that Glorious History is complete in the tech tree

5. Go to planet map and select land space, the Stellar Forge is not in by possible build queue

I went to the ship yard and found that the light constructor module was available so I know that the tech logic is working, some what.  I also tried the Tholian race to double check that I had the Matrix in the build queue.  Lastly, I tried to reinstall with no success.  After reinstall, I noticed my custom race was still available so maybe it wasn't clean.   Any ideas for me?