The legacy ESX version may not be fully supported by the latest version of vRanger.
Ex: ESX 4.0.0 is older then the oldest supported esx for vRanger 6.1 - ESX 4.1 Update 3.
Also, VM's that may have originally been on the older ESX(i) versions may not have the most current VMware tools.
Please see the vRanger 6.1 Installation and upgrade guide for all compatibility and system requirements.
https://support.quest.com/technical-documents/book/1595
In some instances we found that the VMware tools on the failing VM's showed "out of date".
After upgrading VMware tools, the backup jobs would run.
