How to simulate object flows in an activity diagram please?

[Volkan]

Hi there! When I draw an activity diagram, I linked two actions by an object flow. But the simulation did not work at all for the object flows. I had to add additional control flows to do the simulation succefully. Is it I use the object flows in the wrong way? Or object flows are just not simulated? If object flows cannot be simulated, how about the action pins? Thank you very much!