How to Resolve "Error during backup initialization" VSS Error

Systems running firmware version 6.6.0 or newer includes a new feature that will check for items from the system state that may suddenly go missing. This prevents backups from being marked successful when critical items are missing. However, there are certain cases where a user intentionally uninstalled a component, such as a WINS writer. These events will cause the following error  "Error during backup initialization: Not found. The Windows Internet Name Service VSS Writer was not found. This VSS writer was present during the previous backup."

If the VSS writer was not removed intentionally, 

1. Reboot the server. Often times, that will resolve basic VSS issues and correct writer related problems without further interaction. Keep in mind that rebooting a server in a production environment is often not a viable option and downtime must be scheduled.
2. Check the status of the VSS Writers and VSS Providers using the following syntax in an admin command prompt. It is also important to check Event Viewer for additional error information.

   1. vssadmin list writers – Lists the writers and their current state. Ensure that all of the VSS writers are stable and that they are not reporting an error. Take note of any writer that is not in a stable state and restart the respective service related to that writer. Run the same command again to ensure the writer has returned to a stable state. 
      Note: Services often have dependencies and when a service is reset it will be required to reset them as well. This process can momentarily result in loss of service while being reset.

If the VSS writer was removed intentionally, to disable or ignore the missing writer,

1. Stop the Backup Agent service.
2. Run notepad.exe as an administrator and open the following config.ini file c:/program files/barracuda/barracuda backup agent/config/config.ini
3. Add the following lines to the bottom of the file based on the options:

   1. To ignore the specific writer:
      [configuration]
missingWriterIgnoreList=<WRITER_NAME_FROM_ERROR> 

      For example, for this error Error during backup initialization: Not found. The Windows Internet Name Service VSS Writer was not found. This VSS writer was present during the previous backup., add the following lines:
      [configuration]
missingWriterIgnoreList=Windows Internet Name Service

   2. To disable the feature to detect a missing writer:
      [configuration]
disableDeltaWriterDetection=yes
4. Save the config.ini file.
5. Restart the Backup Agent service.