I remember in the original Strife the user was able to use number keys1,2,3 to answer certain questions from NPCs. But with the Veterans Edition, pressing the number keys does nothing. Is there any way to fix this?

The VE changes it to a more modern RPG standard where you use the mouse to select the answer you want. I don't think you can turn it back into using number keys. That's only working in the old DOS version of the game.

You can still use the number keys just make sure the mouse cursor is hidden in the corner or something.