This article describes how to rename backup locations in on-premise version of Acronis Backup 12.5.
(!) Acronis Secure Zone locations and tape pools cannot be renamed.
Solution
How to rename an unmanaged location
In Management Console, go to Backups > Locations.
Check the checkbox on the backup location that you want to rename (if no checkboxes appear, hover the mouse over the backup location). Menu will appear on the right.