Vagrant error: Your VM has become inaccessible.

If you are getting this error you have probably deleted a virtual machine file, which is still referenced by one of your projects. Trying to run vagrant up or vagrant reload will give the following error message:

Your VM has become “inaccessible.” Unfortunately, this is a critical error with VirtualBox that Vagrant can not cleanly recover from. Please open VirtualBox and clear out your inaccessible virtual machines or find a way to fix them.

So why this happens? Vagrant creates a hidden folder within your project directory named .vagrant with files that refer to specific virtual machine IDs.

Open your terminal, cd into your project folder and delete the .vagrant folder, like this:

$ rm -rf .vagrant

Then run again this command:

$ vagrant up

Vagrant will rebuild the .vagrant directory with the correct files and ID.