Acronis Backup Cloud: backup format is shown as "unknown" in Backups tab after Datacenter is updated to Acronis Cyber Cloud 8.0

You have existing backup created with Agent build 12960 or older version. Data center is updated to Acronis Cyber Cloud 8.0 (list of released versions - https://kb.acronis.com/content/56310)

You go to "Backup" tab, choose location and see "unknown" value in "Backup format" column.