首先是错误提示：

Vagrant was unable to mount VirtualBox shared folders. This is usually

because the filesystem "vboxsf" is not available. This filesystem is

made available via the VirtualBox Guest Additions and kernel module.

Please verify that these guest additions are properly installed in the

guest. This is not a bug in Vagrant and is usually caused by a faulty

Vagrant box. For context, the command attempted was:

mount -t vboxsf -o uid=1000,gid=1000 vagrant /vagrant

The error output from the command was:

mount: unknown filesystem type 'vboxsf'

然后谷歌后手动下载vagrant插件 vagrant-vbguest 

可是该插件下载失败，大神们  有什么解决方案！