ローカル開発環境の構築）vagrant up　ができない

前提・実現したいこと

ドットインストールのローカル開発環境構築というものを見て進めています。
virtualboxとvagrantを使って仮想マシンを立ち上げる際にvagrant up　がうまくいきません

発生している問題・エラーメッセージ

>vagrant up
Bringing machine 'default' up with 'virtualbox' provider...
==> default: Box 'bentontos-6.8' could not be found. Attempting to find and install...
    default: Box Provider: virtualbox
    default: Box Version: >= 0
C:/HashiCorp/Vagrant/embedded/mingw64/lib/ruby/2.4.0/uri/rfc3986_parser.rb:67:in `split': bad URI(is not URI?): file:///C:/Users/taisu/MyVagrant/MyCentOS/bentontos-6.8 (URI::InvalidURIError)
        from C:/HashiCorp/Vagrant/embedded/mingw64/lib/ruby/2.4.0/uri/rfc3986_parser.rb:73:in `parse'
        from C:/HashiCorp/Vagrant/embedded/mingw64/lib/ruby/2.4.0/uri/common.rb:231:in `parse'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/builtin/box_add.rb:485:in `metadata_url?'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/builtin/box_add.rb:91:in `block in call'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/builtin/box_add.rb:89:in `map'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/builtin/box_add.rb:89:in `call'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/warden.rb:50:in `call'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/builtin/before_trigger.rb:23:in `call'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/warden.rb:50:in `call'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/builder.rb:116:in `call'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/runner.rb:102:in `block in run'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/util/busy.rb:19:in `busy'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/runner.rb:102:in `run'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/builtin/handle_box.rb:82:in `handle_box'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/builtin/handle_box.rb:42:in `block in call'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/builtin/handle_box.rb:36:in `synchronize'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/builtin/handle_box.rb:36:in `call'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/warden.rb:50:in `call'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/builtin/before_trigger.rb:23:in `call'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/warden.rb:50:in `call'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/warden.rb:121:in `block in finalize_action'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/warden.rb:50:in `call'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/builder.rb:116:in `call'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/runner.rb:102:in `block in run'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/util/busy.rb:19:in `busy'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/runner.rb:102:in `run'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/builtin/call.rb:53:in `call'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/warden.rb:50:in `call'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/builtin/before_trigger.rb:23:in `call'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/warden.rb:50:in `call'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/builtin/after_trigger.rb:26:in `call'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/warden.rb:50:in `call'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/plugins/providers/virtualbox/action/check_virtualbox.rb:26:in `call'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/warden.rb:50:in `call'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/builtin/before_trigger.rb:23:in `call'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/warden.rb:50:in `call'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/builder.rb:116:in `call'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/runner.rb:102:in `block in run'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/util/busy.rb:19:in `busy'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/action/runner.rb:102:in `run'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/machine.rb:238:in `action_raw'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/machine.rb:209:in `block in action'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/environment.rb:613:in `lock'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/machine.rb:195:in `call'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/machine.rb:195:in `action'
        from C:/HashiCorp/Vagrant/embedded/gems/2.2.5/gems/vagrant-2.2.5/lib/vagrant/batch_action.rb:86:in `block (2 levels) in run'

該当のソースコード

# 今後複数の仮想マシンを作ることを想定して、それらをまとめるフォルダ（MyVagrant）を作る
mkdir MyVagrant

# MyVagrantに移動する
cd MyVagrant

# 仮想マシンを作るフォルダを作る（MyCentOS）
mkdir MyCentOS

# MyCentOSに移動する
cd MyCentOS

# 仮想マシン設定用のVagrantfileを作る
vagrant init bento/centos-6.8

# Vagrantfileを編集して仮想マシンのIPアドレスを192.168.33.10にする
(動画をご覧ください)

# 仮想マシンを起動する（少し時間かかります）
vagrant up

試したこと

補足情報（FW/ツールのバージョンなど）

windows10
virtualbox 6.0.4
vagrant 2.2.5
よろしくお願いします。

###追記

vagrantfile
1# -*- mode: ruby -*-
2# vi: set ft=ruby :
3
4# All Vagrant configuration is done below. The "2" in Vagrant.configure
5# configures the configuration version (we support older styles for
6# backwards compatibility). Please don't change it unless you know what
7# you're doing.
8Vagrant.configure("2") do |config|
9  # The most common configuration options are documented and commented below.
10  # For a complete reference, please see the online documentation at
11  # https://docs.vagrantup.com.
12
13  # Every Vagrant development environment requires a box. You can search for
14  # boxes at https://vagrantcloud.com/search.
15  config.vm.box = "bento\centos-6.8"
16
17  # Disable automatic box update checking. If you disable this, then
18  # boxes will only be checked for updates when the user runs
19  # `vagrant box outdated`. This is not recommended.
20  # config.vm.box_check_update = false
21
22  # Create a forwarded port mapping which allows access to a specific port
23  # within the machine from a port on the host machine. In the example below,
24  # accessing "localhost:8080" will access port 80 on the guest machine.
25  # NOTE: This will enable public access to the opened port
26  # config.vm.network "forwarded_port", guest: 80, host: 8080
27
28  # Create a forwarded port mapping which allows access to a specific port
29  # within the machine from a port on the host machine and only allow access
30  # via 127.0.0.1 to disable public access
31  # config.vm.network "forwarded_port", guest: 80, host: 8080, host_ip: "127.0.0.1"
32
33  # Create a private network, which allows host-only access to the machine
34  # using a specific IP.
35  config.vm.network "private_network", ip: "192.168.33.10"
36
37  # Create a public network, which generally matched to bridged network.
38  # Bridged networks make the machine appear as another physical device on
39  # your network.
40  # config.vm.network "public_network"
41
42  # Share an additional folder to the guest VM. The first argument is
43  # the path on the host to the actual folder. The second argument is
44  # the path on the guest to mount the folder. And the optional third
45  # argument is a set of non-required options.
46  # config.vm.synced_folder "../data", "/vagrant_data"
47
48  # Provider-specific configuration so you can fine-tune various
49  # backing providers for Vagrant. These expose provider-specific options.
50  # Example for VirtualBox:
51  #
52  # config.vm.provider "virtualbox" do |vb|
53  #   # Display the VirtualBox GUI when booting the machine
54  #   vb.gui = true
55  #
56  #   # Customize the amount of memory on the VM:
57  #   vb.memory = "1024"
58  # end
59  #
60  # View the documentation for the provider you are using for more
61  # information on available options.
62
63  # Enable provisioning with a shell script. Additional provisioners such as
64  # Puppet, Chef, Ansible, Salt, and Docker are also available. Please see the
65  # documentation for more information about their specific syntax and use.
66  # config.vm.provision "shell", inline: <<-SHELL
67  #   apt-get update
68  #   apt-get install -y apache2
69  # SHELL
70end