vagrant upで接続できなくなり困っています。

###前提・実現したいこと
vagrant upで接続できなくなり困っています。
virtualboxからは普通にログインできます。
どうか、ご教示くださいm(__)m

###発生している問題・エラーメッセージ

エラーメッセージ

myvagrant\ubuntu1604> vagrant up
Bringing machine 'default' up with 'virtualbox' provider...
==> default: This machine used to live in C:/Users//Myvagrant/ubuntu1604 but it's now at C:/Users//myvagrant/ubuntu1604.
==> default: Depending on your current provider you may need to change the name of
==> default: the machine to run it as a different machine.
==> default: Clearing any previously set forwarded ports...
==> default: Clearing any previously set network interfaces...
==> default: Preparing network interfaces based on configuration...
default: Adapter 1: nat
default: Adapter 2: hostonly
==> default: Forwarding ports...
default: 3001 (guest) => 3001 (host) (adapter 1)
default: 22 (guest) => 2222 (host) (adapter 1)
==> default: Booting VM...
==> default: Waiting for machine to boot. This may take a few minutes...
default: SSH address: 127.0.0.1:2222
default: SSH username: vagrant
default: SSH auth method: private key
Timed out while waiting for the machine to boot. This means that
Vagrant was unable to communicate with the guest machine within
the configured ("config.vm.boot_timeout" value) time period.

If you look above, you should be able to see the error(s) that
Vagrant had when attempting to connect to the machine. These errors
are usually good hints as to what may be wrong.

If you're using a custom box, make sure that networking is properly
working and you're able to connect to the machine. It is a common
problem that networking isn't setup properly in these boxes.
Verify that authentication configurations are also setup properly,
as well.

If the box appears to be booting properly, you may want to increase
the timeout ("config.vm.boot_timeout") value.

###該当のソースコード

###試したこと

###補足情報(言語/FW/ツール等のバージョンなど)
windows10 64bit
ubuntu 16.04
vagrant 2.0.1
virtualbox 5.2.2