Install fails due to undefined method

[jelo77]

Hi,

I followed the instructions to set up Drupal VM. Installed Vagrant and Virtualbox. As soon as I try to do "vagrant up" in the command line on a Windows 7 machine, I can observe in my Virtual Box GUI that the script starts creating VMs, one called packer-ubuntu-16.04-amd64_... and one called drupalvm.dev (which quickly shows as running). The command line shows all steps are being executed correctly until we get to mounting shared folders. Immediately after mounting it states:
Forcing shutdown of VM...
Destroying VM and associated drives...
HashiCorp/Vagrant/embedded/gems/gems/vagrant-1.8.6/plugins/guests/linux/cap/mount_virtualbox_shared_folder.rb:64:in 'mount_virtualbox_shared_folder': undefined method '+' for nil:NilClass (NoMethodError)
Then there are plenty of other Vagrant errors.

After this the GUI of VirtualBox shows that the VM with the name drupalvm.dev disappears. The packer-ubuntu one stays as powered off.

Running vagrant provision as suggested in the instructions only leads to "drupalvm: VM not created. Moving on...".

Any idea what is going on?

[jelo77]

Sorry, missed this issue before: #912. Seems to be my problem...