スリープ状態にすると
The guest machine entered an invalid state while waiting for it to boot. Valid states are 'starting, running'. The machine is in the 'paused' state. Please verify everything is configured properly and try again. If the provider you're using has a GUI that comes with it, it is often helpful to open that and watch the machine, since the GUI often has more helpful error messages than Vagrant can retrieve. For example, if you're using VirtualBox, run `vagrant up` while the VirtualBox GUI is open. The primary issue for this error is that the provider you're using is not properly configured. This is very rarely a Vagrant issue.
となってしまいました。 halt の後 reload をしてもだめで、VirtualBoxマネージャーからシャットダウンして再度 up することで再開できました。 古森さん、西川さん、ありがとうございました。