I was getting the blue screen of death after hitting 'engage' from the launcher. I usually open the game from Steam. I fixed it by downloading the official launcher "Star Trek Online.exe" in the stickied thread "# 1 Get Latest Sto Launcher Here!" and replacing the one in my Steam folders.
After replacing the "Star Trek Online.exe" i correctly downloaded the latest 500mb patch with the new voth dreadnought.
Also of note, previously on my character selection screen, my jemhadar and breen officers did not appear correctly, just parts of them floating in the air. After using the newest .exe they appeared correctly. Perhaps this will fix other graphical errors too?