Error: Failed to re-enable existing scheduled backup settings. The server must be registered with Microsoft Azure Backup before this operation can be performed

I've the need to restore a old backup from a different vault than I currently use. But I get the error:

Failed to re-enable existing scheduled backup settings. The server must be registered with Microsoft Azure Backup before this operation can be performed.

I've uninstalled the Azure Backup software, re-installed it again. Selected the old vault credentials (downloaded it freshley)  but the error remains.

When I try to register the server (Register Server Wizard) I get the same issue.

How can I restore from another vault (on another account) to my computer?