Well, you still haven't told us when your game crashes.
Does it crash when you open the game? Or does it crash only when you try to access your new units? Or maybe it crashes during the AI's turns.
In general though, if you haven't used the editor before, I'd recommend NOT changing too many things at once. Try changing one unit at a time, testing it, then go on to the next.
Also, when you do make a change, especially when making a new unit or a new tech, you need to compare your new unit/tech with something similar that already exists, and making sure that all the required fields are filled out.