Keyboard Arrow commands not working

I have been using the Easel 3D software since it was in beta. This problem only occurs when doing 3D and on doing the finishing cut. The software no longer responds to using the arrow keys to move the machine head. I can move the head using the arrow keys before doing the finishing cut and after without reloading on the next 2D and 3D all within the same project, what am I doing or have wrong? This condition has been there since the 3D beginning. 2D works fine.