The issue occurs when the Windows server has Application-consistent quiescing enabled and the virtual machine has more than 7 disks attached to one SCSI controller.
Resolution
To resolve this issue, use one of these options:
Add an additional controller to the virtual machine, so that there are sufficient empty disk nodes on the controllers for the snapshots.
To add an additional controller when the virtual machine is running, add a new disk and in the Advance Options step, change the Virtual Device Node to use another controller. For example, use SCSI 1 instead of SCSI 0.
When the virtual machine is down, you can add another controller without adding a new disk. To add another controller, edit the settings of one of the existing disks and change Virtual Device Node to use a different controller.