Hi and welcome to the forum!
Not sure what is going on there (with ecosystem), Im sure the playmaker experts will help you with making the ecosystem work but in the meanwhile:
Go here:
https://hutonggames.fogbugz.com/?W1031Download the mecanim proxy manually and import it into your project.
After importing you will have the action you need ('set animator float') and the rest of mecanim actions.
Im not sure if you will need to remove the proxy that you already tried to import from the ecosystem or not, but may be something to try if it says you have nothing to import when you drag in the manually downloaded file.
Hopefully this will let you progress and worry about fixing the ecosystem later
.
Good luck with it and I hope it helps!
(edit to add: nice tutorial by the way, I found that one quite fun when I did it, I hope you enjoy it too!)