vagrant up などでエラー

D:/HashiCorp/Vagrant/embedded/mingw64/lib/ruby/2.4.0/json/common.rb:156:in `parse': 751: unexpected token at '' (JSON::ParserError)
        from D:/HashiCorp/Vagrant/embedded/mingw64/lib/ruby/2.4.0/json/common.rb:156:in `parse'
        from D:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/vagrantfile.rb:187:in `machine_config'
        from D:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/environment.rb:958:in `block in find_configured_plugins'
        from D:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/environment.rb:956:in `each'
        from D:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/environment.rb:956:in `find_configured_plugins'
        from D:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/environment.rb:983:in `process_configured_plugins'
        from D:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/environment.rb:178:in `initialize'
        from D:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/bin/vagrant:145:in `new'
        from D:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/bin/vagrant:145:in `<main>'

解決方法

Vagrantfile があるディレクトリにある .vagrantfile を削除する。

その上で vagrant destroy して vagrant up する