Large VM backup fail with error "Unable to copy the virtual machine disk using the VMware VixDiskLib

Hi,

Im backing up large VMs (3TB+) direct to tape from a 6.7 vcentre and they are failing with the below error.

I am using the vmware agent, the windows agent is installed on the VM.

Thanks

V-79-57344-38264 - Unable to copy the virtual machine disk using the VMware VixDiskLib.

VixDiskLib_Read() reported the error: The server refused connection
V-79-57344-38264 - Unable to copy the virtual machine disk using the VMware VixDiskLib.

VixDiskLib_Read() reported the error: The server refused connection