The title says it all. I had taken a snapshot earlier of the VM. Later, my machine locked for some reason last night, and I had to reset it hard. Even the magic keys didn’t save me. Everything seemed to come up ok, but this morning when I tried to start the VM, it failed with the error:
Cannot open the disk ‘/home/vmguests/WinXP/WinXP-000001.vmdk’ or one of the snapshot disks it depends on. Reason: Failed to lock the file.
I found that by deleting all the .lck folders in the VM directory (as root), I was able to start it normally.