Required Port 443 For Veeam Backup & Replication Is Occupied By Another Application -

Open IIS Manager, select the site, click Bindings in the right pane, edit the HTTPS binding, and change port 443 to an unused port (e.g., 8443).

In multi-component installations: If Veeam Backup Enterprise Manager is already installed on the same server, it may have bound port 443 before the main Backup & Replication service. Open IIS Manager, select the site, click Bindings