In the meantime, consider trying what was suggested in this post:
Do tasks 1-5 as instructed. All that is correct. Before running the model in Task 5 try this:
Check the settings on the "Rotational electromechanical converter" block that your "ideal rotational motion sensor" is connected to. Go to the "Variables" tab, check the override box for "Angular velocity" and set priority to "high". Everything else, leave it the way it is. Then run the model. This worked for me because I was having this exact problem.