If you look at the disk that the VM is running on, is there a number appended to the drive? (Ex. -00001?)
This should not be halting the machine unless there is a space issue.
The consolidation option is grayed out. (no active snapshot), even if I try to create a new snapshot, and then delete all, the consolidation is not being enabled,
You are saying I can remove those files (appended) from the list?
Browse that particular datastore and see how many delta disks are there. if your VM folder is having a mulitple delta disk then we might have to consolidate using ESXCLI. Please follow the kb article to remove that delta using ESXCLI.