This morning my work laptop rebooted and installed Windows 10 Anniversary. When I tried to run vagrant up I ran into some problems:

> vagrant up devel
Bringing machine 'devel' up with 'virtualbox' provider...
==> devel: Checking if box 'ubuntu/trusty64' is up to date...
==> devel: A newer version of the box 'ubuntu/trusty64' is available! You currently
==> devel: have version '20160318.0.0'. The latest is version '20160926.0.1'. Run
==> devel: `vagrant box update` to update.
==> devel: Clearing any previously set forwarded ports...
==> devel: Clearing any previously set network interfaces...
==> devel: Preparing network interfaces based on configuration...
    devel: Adapter 1: nat
    devel: Adapter 2: hostonly
==> devel: Forwarding ports...
    devel: 22 (guest) => 10422 (host) (adapter 1)
    devel: 80 (guest) => 10480 (host) (adapter 1)
==> devel: Running 'pre-boot' VM customizations...
==> devel: Booting VM...
There was an error while executing `VBoxManage`, a CLI used by Vagrant
for controlling VirtualBox. The command and stderr is shown below.

Command: ["startvm", "6e7619dd-3bbb-41d8-a4af-c10dadb4175c", "--type", "headless"]

Stderr: VBoxManage.exe: error: The virtual machine 'devel' has terminated unexpectedly during startup with exit code -1073741819 (0xc0000005)
VBoxManage.exe: error: Details: code E_FAIL (0x80004005), component MachineWrap, interface IMachine

The only solution I found to this was to:

  1. Uninstall VirtualBox
  2. Install the current version of VirtualBox
  3. Update Vagrant
  4. Reboot

Just in case someone else needs help. :-)