Recently had a virtual machine show up with a disk size of 0MB in the Vmware client. The machine was still running however Veeam backups were failing.

Checking the snapshots on this machine showed there was none however opening the VM folder in the datastore showed there were loads of snapshot files.

Running a consolidate on the Vmware Snapshots , then helped list the Snapshots which could be removed by the client 

Removing the VM from the Esxi Host and re-adding this should do the same thing

***Update***

Also try removing the CDRom Mapping if it maps to an Inactive NFS share