VM Failed to change state - object is in use - Errors 12010 12030 12040

Windows 2012 R2 installed with raid 1
(host and VMs w2012r2)
Additional Raid 5  with two Volumes, each has its own VM, 1TB each. Volume 1, VM 1 ok, but Volume 2 shows almost full  at the host but VM2 its only 300GB! After compacting VM2, the VM Failed to change state and states the object is in use. After reading a few posts about the Error IDs, I have already checked the Antivirus exceptions and removed the CD/DVD but still won't start! Any hints? 
tks