If you encounter this conflict, identify the application using port 443 and apply the relevant solution: Hyper-V Replication Conflict
[Isolate Conflict] ──> [Stop Conflicting App] ──> [Run Veeam Upgrade/Install] ──> [Apply Network Workarounds]
: Web servers hosted on the same machine often default to 443 for HTTPS. If you encounter this conflict, identify the application
sc query W3SVC
: Terminating a process may cause the conflicting application to crash or lose unsaved data. Open Task Manager ( Ctrl + Shift + Esc ). Go to the Details tab. Go to the Details tab
The error occurs because Veeam Backup & Replication (VBR) v13 introduced a hardcoded, mandatory requirement for TCP port 443 to host its REST API Gateway and Web UI . If another service (such as IIS, Apache, VMware Horizon, or Hyper-V Replication) is already listening on port 443, the Veeam installation or upgrade installer will block. Because this port is hardcoded into VBR v13, the only supported solution is to identify the conflicting application and reconfigure or move it to a different port . Why Veeam Backup & Replication Now Mandates Port 443
Once the upgrade completes, you may attempt to re-enable the third-party service on a different port. Registry Fix (Veeam Agents only) For standalone Veeam Agents Because this port is hardcoded into VBR v13,
: Alternatively, Veeam Backup & Replication can be configured to use a different port for its operations, though this might require additional configuration in network and security settings.
Alternative backup solutions, remote management tools, and various enterprise applications frequently use port 443 for their web interfaces.