Interesting article on how to stop an unresponsive VM.
this happened to me https://phonelookupbase.com , when one of my users came to me, telling me, that her undeployment in LabManager 4 would never finish. Looking at the ESX host itself, I see the „Power down virtual machine“ task hanging at 95%. used the vm-support script to kill it, as it did allow hard stop command before.
VMware KB: Powering off an unresponsive virtual machine on an ESX host.