If a Virtual Machine's MoRef is changed due to migration to new vCenter / inventory change in vCenter, you would receive the error "Object "vmname" is not found". Please see KB1299 for more details.
This utility is designed to assist in re-mapping the MoRef ID's of the Virtual Machines you are backing up and/or replicating using Veeam Backup & Replication, so that backup incremental chains remain intact, after an inventory change in VMware vSphere vCenter. Do not run any jobs before using the migration tool otherwise, the migration process won't be possible.
Important! If you are migrating to a 6.5U2 VCSA, VMware has a new migration utility, which could preserve existing VM MoRef IDs:
https://blogs.vmware.com/vsphere/2016/09/vcenter-server-migration-tool-vsphere-6-0-update-2m.html
https://blogs.vmware.com/vsphere/2017/01/vcenter-server-appliance-6-5-migration-walkthrough.html
This VMware utility only works for a 5.5 VC to a 6.5U2 VCSA!
Veeam Backup & Replication tracks Virtual Machines in its jobs by a Managed Object Reference ID (MoRef), which will change when moved to another vCenter, or removed and re-added to inventory.
Please download this bundle: tool and instructions.
Before using this tool, it is highly recommend to take a configuration backup of your VeeamBackup database.
Note:
If you use the VMware provided VCSA Migration tool, you will need to remove and re-add VMs to jobs manually through the new VCSA after adding it to Veeam.
VMware highly recommends migrating to a VCSA, as they are phasing out the Windows based vCenter.
https://blogs.vmware.com/vsphere/2017/08/farewell-vcenter-server-windows.html