Can you post your script on the community (community.cgcookie.com)? I can take a look to see what the issue is. The only thing I can think of is that you’re trying to access the emission rate from the particle system instead of the particle system emission module.
I’ve tested this myself using the scripts shown in the video in Unity 2017 and it works fine other than a warning to use the “RateOverTime”, but it will still work with what is shown in the video.