virtualbox.org

I was copying some files within an Ubuntu VM and wasn't paying attention to the space on the host. The host machine ran low/out of space and the VM paused. I cleared up plenty of space and tried to start the machine and it wouldn't. I get this error:

Failed to open the hard disk C:\Users\Administrator\VirtualBox VMs\UBUNTUBOX\UBUNTUBOX-disk1.vmdk.

Could not get the storage format of the medium 'C:\Users\Administrator\VirtualBox VMs\UBUNTUBOX\UBUNTUBOX-disk1.vmdk' (VERR_NOT_SUPPORTED).

Result Code: VBOX_E_IPRT_ERROR (0x80BB0005)
Component: Medium
Interface: IMedium {53f9cc0c-e0fd-40a5-a404-a7a5272082cd}
Callee: IVirtualBox {c28be65f-1a8f-43b4-81f1-eb60cb516e66}

I'm on a Windows 2008 R2 host. Is there any way to recover?

I guess I'll leave this mystery for another day - restored from a backup.