Am I missing something serious because whenever I play Endless Space and research the tech to get the Destroyer ship class I don't actually unlock the destroyer, I just advance the tech tree and if I go onto the ship building menu it is still unavailable. It becomes really annoying as i end up getting attacked by a Scout, declaring war to blow it up but just get annihilated by the enemies fleet of Destroyers. They beat me every time!!!

In the fleet design window, please push the "add" button. Please also read Raptor's FAQ, linked below, and browse the thread titles in the FAQ forum.