Hello,
there's an issue since the introduction of the Eden editor. Topography and exportnogrid is NOT working on Eden despiste seeing the right message (ie activated topography).
This is only working on the old 2D editor.
To run it, you need to click on the editor box at the start menu. Select your map but do not press OK. Instead, press CTRL O. You will end up in the 2D editor.
Now, do the usual steps (shift - then topography or exportnogrid). You will NOT see any message on screen.
Quit Arma.
check you C:\ and enjoy your emf file !