When I click on a menu item, the corresponding window is not visible

The window is probably appearing in a location that is not on the screen.  Perhaps you ran Fires in full screen mode last time, but are running it in windowed mode now.  Alternatively you may be using a different resolution.  It is possible that the window you desire is located outside the visible desktop area.  You have three options:

1. Maximize the application, drag the window to the desired position and then resize the application to your desired size.
2. Go to Toolbar → Window → Retrieve Out Of Screen Windows.  This will fetch any windows displayed outside the visible desktop and bring them to the edge of the visible area.
3. Go to Toolbar → Window → Cascade Windows.  This will cascade all relevant windows and should move your desired window into the current view.