Full VM backup problem with error code ANS9351E

[trax020]

Hello all,

I'm trying to implement Full VM Incremental Forever backup of VMware 5.1 virtual machines.
I'm scheduling a script which invoke a command such as dsmc backup vm...
First time it runs fine, but from 5 days ago I'm getting the following message:

Creating snapshot for virtual machine 'Srv_WMS'Backing up Full VM configuration information for 'Srv_WMS'
18,399 VM Configuration [Sent]
Deleted directory C:\Windows\TEMP\vmware-SYSTEM\564d3a24-2f66-6a7a-fd59-abb0ff77ab1e-vm-33\san
ANS9351E Data was not available on server and was skipped.
ANS4174E Full VM backup of VMware Virtual Machine 'Srv_WMS' failed with RC=40 mode=Incremental Forever - Incremental, target node name='SRV-BACKUPPROXY', data mover node name='SRV-BACKUPPROXY'


ANS1228E Sending of object 'Srv_WMS' failed
ANS9351E Data was not available on server and was skipped.
Statistics for Virtual Machine 'Srv_WMS'.


Total number of objects inspected: 1
Total number of objects backed up: 0
Total number of objects updated: 0
Total number of objects rebound: 0
Total number of objects deleted: 0
Total number of objects expired: 0
Total number of objects failed: 1
Total number of subfile objects: 0
Total number of bytes inspected: 17.96 KB
Total number of bytes transferred: 0 B
LanFree data bytes: 0 B
Data transfer time: 0.00 sec
Network data transfer rate: 0.00 KB/sec
Aggregate data transfer rate: 0.04 KB/sec
Objects compressed by: 0%
Total data reduction ratio: 0.00%
Subfile objects reduced by: 0%
Elapsed processing time: 00:06:50
Removing snapshot for virtual machine 'Srv_WMS'

Any idea? Thank you in advance