When attempting a backup of a number of Virtual Machines, they intermittently fail with "Error Message: The transaction does not exist to call rollback on!"
On closer inspection of the job, cataloging is turned on. Yet, it appears that cataloging is not available as a service - you can check this in Tools | Options | Job Configuration | Cataloging
In the short term, you can back up your environment with cataloging turned off - this will stop the errors from occuring.
The reason why the cataloging service is not available has to be investigated. The cataloging component may have got corrupt during an upgrade.
To reinstall the catalog manager please follow this knowledgebase article: https://support.quest.com/SolutionDetail.aspx?id=SOL76817
If that does not resolve your issue, you will need to do a full uninstall of vRanger, then a full install of vRanger without the cataloging component, then run the full installer again, this time selecting the cataloging component only. You will need to backup your vRanger Database prior to doing this. Instructions for backing up your vRanger Database can be found at: https://support.quest.com/SolutionDetail.aspx?id=SOL77403
