Issue
During the Interface Engine installation, you may receive the error:cannot open backup device

This typically occurs because the SQL Server service is running under a network service account that does not have sufficient permissions to access the backup file or device.

Resolution
To resolve this issue, change the SQL Server service account to the Local System account and then rerun the installer:

Log on to the database server with an account that has administrative privileges.
Open the Services management console
Press Win+R, type services.msc, and press Enter.
Locate the SQL Server service
The default instance is usually named SQL Server (MSSQLSERVER).
For named instances, look for SQL Server (<InstanceName>).
Right-click the SQL Server service and select Properties.
Go to the Log On tab.
Change the service account to Local System account.
If it is currently set to Network Service or another network account, select Local System account instead.
Click Apply, then OK.
Restart the server to ensure the change takes effect.
After the server restarts, re-run the Interface Engine installer.