エラー内容

新規の仮想環境作りの時に、Vagrant 1.8.7がpluginsエラーで一切立ち上がらなくなってしまいました。
出てたエラーは下記のものです。

C:>vagrant
Bundler, the underlying system used to manage Vagrant plugins,
is reporting that a plugin or its dependency can't be found.
This is usually caused by manual tampering with the 'plugins.json'
file in the Vagrant home directory. To fix this error, please
remove that file and reinstall all your plugins using `vagrant
plugin install`.
C:/HashiCorp/Vagrant/embedded/gems/gems/bundler-1.12.5/lib/bundler/resolver.rb:356:in `block in verify_gemfile_dependencies_are_found!': Could not find gem 'vagrant-fabric x86-mingw32' in any of the gem sources listed in your Gemfile or available on this machine. (Bundler::GemNotFound)
from C:/HashiCorp/Vagrant/embedded/gems/gems/bundler-1.12.5/lib/bundler/resolver.rb:331:in `each'
from C:/HashiCorp/Vagrant/embedded/gems/gems/bundler-1.12.5/lib/bundler/resolver.rb:331:in `verify_gemfile_dependencies_are_found!'
from C:/HashiCorp/Vagrant/embedded/gems/gems/bundler-1.12.5/lib/bundler/resolver.rb:200:in `start'
from C:/HashiCorp/Vagrant/embedded/gems/gems/bundler-1.12.5/lib/bundler/resolver.rb:184:in `resolve'
from C:/HashiCorp/Vagrant/embedded/gems/gems/bundler-1.12.5/lib/bundler/definition.rb:200:in `resolve'
from C:/HashiCorp/Vagrant/embedded/gems/gems/bundler-1.12.5/lib/bundler/definition.rb:140:in `specs'
from C:/HashiCorp/Vagrant/embedded/gems/gems/bundler-1.12.5/lib/bundler/definition.rb:185:in `specs_for'
from C:/HashiCorp/Vagrant/embedded/gems/gems/vagrant-1.8.7/lib/vagrant.rb:76:in `<top (required)>'
from C:/HashiCorp/Vagrant/embedded/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:128:in `require'
from C:/HashiCorp/Vagrant/embedded/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:128:in `rescue in require'
from C:/HashiCorp/Vagrant/embedded/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:39:in `require'
from C:/HashiCorp/Vagrant/embedded/gems/gems/vagrant-1.8.7/bin/vagrant:120:in `<main>'

vagrantも、vagrant upも、vagrant -hも使えない状況です。
vagrant -vだけは使えました。

対策

C:\Users\ユーザ名\.vagrant.d\plugins.jsonというファイルを削除します。
削除して、下記のコマンドを実行してください。

vagrant plugin install gems

実行すると直しました！！！！！

C:>vagrant plugin install gems
Installing the 'gems' plugin. This can take a few minutes...
Installed the plugin 'gems (1.1.1)'!

C:>vagrant
Usage: vagrant [options] <command> [<args>]

-v, --version                    Print the version and exit.
-h, --help                       Print this help.

Common commands:
box             manages boxes: installation, removal, etc.
destroy         stops and deletes all traces of the vagrant machine
global-status   outputs status Vagrant environments for this user
halt            stops the vagrant machine
help            shows the help for a subcommand
init            initializes a new Vagrant environment by creating a Vagrantfile
login           log in to HashiCorp's Atlas
package         packages a running vagrant environment into a box
plugin          manages plugins: install, uninstall, update, etc.
port            displays information about guest port mappings
powershell      connects to machine via powershell remoting
provision       provisions the vagrant machine
push            deploys code in this environment to a configured destination
rdp             connects to machine via RDP
reload          restarts vagrant machine, loads new Vagrantfile configuration
resume          resume a suspended vagrant machine
snapshot        manages snapshots: saving, restoring, etc.
ssh             connects to machine via SSH
ssh-config      outputs OpenSSH valid configuration to connect to the machine
status          outputs status of the vagrant machine
suspend         suspends the machine
up              starts and provisions the vagrant environment
version         prints current and latest Vagrant version

For help on any individual command run `vagrant COMMAND -h`

Additional subcommands are available, but are either more advanced
or not commonly used. To see all subcommands, run the command
`vagrant list-commands`.