These issues have been fixed.  Thanks for pointing them out guys.
~C

Fleet Defense, if you read it's description after researching it, is meant to be a tech that leads to others down the branch.  It's not supposed to unlock anything other than the opportunity to research farther down its branch.

Short description:
A series of technologies that improve the defense rating of all the ships in a given fleet.

Long description:
It is an irony of research that many of the engineered results of technology are impractical for use.  This is the case for many ship defense technologies that have been considered. These technologies do indeed improve the ship's defense rating but at a cost that is so high that it is impractical to use.  However, many of these defense technologies can be adapted to help not just the ship that is using them but other ships in a given fleet.  This adaptation is the purpose of the Fleet Defense technology branch.

I'm guessing that what you mean this time is the Altarian tech "EnhancedDefenses".  That one has already been fixed internally too, along with every other TODO in every tech tree.

Thanks,
~C