Vagrant was unable to mount VirtualBox shared folders

Question

Current setup: Virtualbox 5.1.20 with Vagrant 1.9.3

Previous working setup: Virtualbox 5.1.18 with Vagrant 1.9

Answer 1

What I had to do was run the following command to add nfs to windows

vagrant plugin install vagrant-winnfsd

Source: https://peshmerge.io/how-to-speed-up-vagrant-on-windows-10-using-nfs/