Most developers are accustomed to having the option of renaming certain objects. Unfortunately, the menu bar object is not one of them. Currently, it is not possible to rename a menu bar installed by a component. Whether the status of the object is public, private , or protected, 4th Dimension will not allow the object to be renamed.

Other links that might be of interest:
https://kb.4d.com/assetid=26690 - Renaming a Menu Bar