Challenge
The job fails with error "Failed to open VDDK disk."
Cause
VMware Tools quiescence is not supported for Windows 2008 R2 and Windows 7 running on ESX(i) 4.1 hosts.
Solution
To work around this, enable application-aware processing in the Veeam job settings to leverage Veeam VSS integration. The "Enable VMware tools quiescence" option is disabled by default. It is strongly recommended to leave it disabled if you are backing up or replicating Windows systems that support Windows VSS — for these systems, it is recommended to use the "Enable applicationaware image processing" option.
More Information
The issue will be fixed in version 6.