I am getting this error with this line in my Vagrantfile during vagrant up, until I comment it out.
The setting is documented here:
http://docs-v1.vagrantup.com/v1/docs/config/vm/share_folder.html
Not sure why the following documented paramenter causes an error
config.vm.share_folder "puppetdir", "/etc/puppet", "/vagrant/mypuppetdir"
Bringing machine 'default' up with 'virtualbox' provider...
There are errors in the configuration of this machine. Please fix
the following errors and try again:
vm:
* The following settings don't exist: share_folder
The latest virtualbox and latest vagrant. everything else works fine.