My Ships won't fire their missiles

[Saxon]

If you have the fast combat on (one of the options) things like missle fire can happen so quickly it is hard to notice. If firing on a planet, you may not notice the effects, as it may just be a population drop.

Try turning that option off. I am reaching, but you never know.

[jc173]

Something that threw me for a loop the first time I played is that the missile doesn't actually go anywhere when it is first fired. Depending on what race you're playing if you're not waiting another turn, the missile icon might be masked by the firing ship since it's in the same map square still.