2013 SP3 isn't out yet.
I had the same problem when I used it last night, using Simulation express.
I was simulationg a simple helix model. I'm using SW2013 SP2.
It easily breaks down and I had to restart SW may times.
I for example had a problems in adding material, it would simply not accept a change. So I had to start SW over may times, until I found the right material.
I can't either find the place where I can change the Scaling factor of the anumation, but I dont think that is a Bug :-)