If you’re unable to load vagrant using vagrant up and the system is hanging on the message default: SSH auth method: private key you may need to reset the operating system that VirtualBox believes it is loading.
VirtualBox has been known to reset the setting from 64bit to 32bit during updates or configuration changes. This causes the box to not load properly whether you are using vagrant or not.
- Open VirtualBox and select your box and click Configurations
- Select the General tab
- Change the version to whatever it was before. It most likely will need to be changed from 32bit to the 64bit version.