This can be due to an incompatibility or corruption of any of the items below or a combination amongst them:
-DR version.
-RDS Plugin.
-OS.
-NVBU version.
Workaround:
Confirm within the latest compatibility guide if a specific/minimum driver, version or firmware is required and/or compatible:
https://support.quest.com/netvault-backup
*As of NV 10.0.5.x the RDA library is included as part of the platform installation. If there's an improper or corrupt NetVault installation, this could be another cause for this error and reinstalling NV would be another possible solution.