Unable to add standalone drive to a virtual Smart Client residing on an ESXi 5.x Server. (4037042)

Unable to add standalone drive to a virtual Smart Client residing on an ESXi 5.x Server.

NVS: NVBU 10.0.0.46 Windows 2008 R2 Standard Physical Machine.
NVSC: NVBU 10.0.0.46 Windows 2008 R2 Standard VM on an ESXi 5.0 Server.
Standalone Drive: is an HP 1840 LTO-4 drive connected to the Smart Client via SAS.

When you attach a backup device to a Client, then this becomes a Smart Client and will therefore need to have a Smart Client entry in your NetVault Server main license key.
This will in turn open up the channel from the NetVault Server to scan all Clients for devices.
You can view what you are licensed for in the NetVault Server Console > Reports > Double click on Server license – capabilities and usage Report.

Note: Always check the NetVault Backup - Supported VTLs, Libraries, Tape and Optical Drives Compatibility Guide on the following link to make sure your device is supported to work with NVBU:

https://support.quest.com/netvault-backup/technical-documents

As per the vSphere 5.x Release Notes, VMware does not support tape drives connected directly to an ESXi 5.x Server.
Additionally VMware does not provide support for backup tape drives and tape library devices or their functionality on ESX/ESXi hosts.
Further information can be found on the following link:

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1016407

As a workaround you can either create a physical Smart Client and attach the standalone drive there, or you can attach the standalone drive to the NetVault Server.