really bad experiences working with disk consolidation not more than 4 days ago had the same situation.
VM with active Snapshot and Disk consolidation needed.
in that case I did consolidation first and failed in fact it powered off the VM and VM could be powered back on anymore.
now I am was trying to do it correctly but it failed too. I have not power on the VM, snapshot was removed but disk consolidation gave me that error where should I check for more log information?