CAMWorks can sometimes not show any cuts during the Simulation. In one case, a customer set up his CAMWorks toolpath properly, but the simulation would not show the cuts. The tool would move, but material would not be removed from the stock.
The Issue was that the stock was pointed in the wrong direction. The simulation was cutting space, and not engaging the stock. It is important to properly define your stock as the first step in using CAMWorks.