Backup Windows 2003 VMs failed on VSC 4.2.1P1

[Wu]

I always see error VMware Task "CreateSnapshot_Task" for entity "xxx" failed with the following error: An error occurred while saving the snapshot: Failed to quiesce the virtual machine on Windows 2003 VM. My ESXi version  is 5.5 U1, VMware Tools is up to date.

Any trick to fix it?

[YIshikawa]

Snapshot task on VMware faild, so it is better to check if you are able to create VM snapshot on vSphere Client.