I have PLCSIM V13. I create the program, Save it and compile it.But the Start simulation is in inactive stage.What I do.This is the steps I'm following in S7 300 and 400 and even S71500.
One of the problems I had was that I didn't have all the support packages from the TIA updater. After downloading and installing all them I could create a new project and simulate it.
I could also sim my old project by making a new project, setting up hardware and then copying over the blocks one by one.