When Symantec VSS (Volume Snapshot Service) is uninstalled freeze.bat is not removed resulting in VM Ware snapshots failing with status 156.
VM Snapshot creation failed status 156:
Cannot create a quiesced snapshot because the (user-supplied)
custom prefreeze script in the virtual machine exited with a
nonzero return code.
NetBackup VSS Provider is installed then uninstalled.
Manually remove the script "freeze.bat" from the following location:
“C:\Program Files\VMware\VMware Tools\backupscripts.d”
NetBackup 7.5 VMWare for Microsoft Exchange option.