“Some Agents were not processed during the copy interval.”
“Some VMs were not processed during the copy interval.”
Errors similar to above can occur for periodic backup copy jobs created prior to VBR v12. This means that the job was actively transmitting data, or had not gotten a new version of the backup to copy when the copy interval expires.
The resolution will differ depending on the cause. you may have an issue with the primary backup job used as the source that delayed its availability for the backup copy job to process. If this happens repeatedly, you can adjust the scheduling of the backup copy job.
For example: if you want the backup copy job to run every 24 hours, make the copy interval start the same time as the local backup job it sources data from. This ensures the backup copy job processes the source items as they complete in the primary job.
For more information on Backup copy jobs for VBR v11 please see the following link:
https://helpcenter.veeam.com/archive/backup/110/vsphere/backup_copy_modes.html
Note that in v12 the processing of periodic backup copy jobs were changed to allow more control over scheduling, so you are not likely to see this error in v12.