I have your plugin installed on a bunch of my sites and it works perfectly. I recently added it for the first time on another site and it won't work and gives the bool(false) error that many have experience.
I read through some of the answers and you mentioned that it might have to do with a php setup on the server but why would it work on most of my sites and not on another.
All of my sites are Wordpress blogs running version 4.0