I've looked into this, and it appears that this problem occurs when copying this command directly from the readme file from mendeley data I posted. It seems that the .rtf format inserts some sort of hidden character that causes this to fail. I'm updating the readme file to be just plain text so that this isn't a problem. 

In the meantime, just directly type the command, or if you like to copy and paste, copy it to another document without formatting and it should work. 

hope that helps!

-Kevin