Universal Print Connect 2.4.9459.590 Service keeps stop /start

I have changed the ports 8095 and that did not do anything same

The connector service repeatedly stopping and the “Failed to initialize authentication. There was no endpoint listening…” dialog indicate a Universal Print Connector service issue rather than a port‑8091 conflict.

Based on the troubleshooting guidance, use the following checks and steps:

1. Confirm connector prerequisites and services
   1. Verify all connector prerequisites are met for the server where the connector is installed (network, OS, required components).
   2. In Services, ensure these services are running and not crashing:
      • Print Connector service (PrintConnectorSvc.exe)
      • Print Spooler (Spoolsv.exe)
2. Verify connector version and update if needed
   1. Download the latest connector installer from the official source.
   2. Compare the version in the MSI file name with the version shown in the connector app title bar. The first three parts (for example, 2.4.x) must match. If they do not, install the newer connector build.
3. Check the connector event log for the crash cause
   1. Open Run and execute:

            eventvwr /c:Microsoft-Windows-PrintConnector/Operational
      

   2. Look for recent errors around the time the service stops, especially:
      • Job failures (for example, XPS_JOB_FAILED)
      • Printer Registration Failure (event ID 8)
      • Any other error that appears just before the service terminates.
   3. Use the error details to identify the failing component (driver, authentication, hybrid AD, etc.). If event ID 27 (AD Hybrid impersonation failed) appears, follow the Hybrid AD troubleshooting guidance.
4. Validate network and Microsoft Entra ID connectivity
   1. Confirm the connector server has outbound Internet access as required in the connector prerequisites (including access to the Universal Print endpoints and Microsoft Entra ID).
   2. If Hybrid AD is enabled in the connector, verify the server can reach Microsoft Entra ID and that the configured account is valid.
5. Confirm printers and drivers on the connector
   1. Ensure the printers installed on the connector are physical devices, not logical queues from third‑party solutions.
   2. Install the latest vendor printer drivers on the connector and, if necessary, follow the documented procedure for changing the printer driver on the connector.
6. If the WCF endpoint conflict reappears If at any point another process starts using port 8091 and the connector shows a “wcf endpoint is not listening” error again, change the connector port:
   1. Identify a free port (for example, 8095).
   2. In an elevated PowerShell window run:

            net stop "print connector service"
            net stop printconnectorupdatersvc
            reg add HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\UniversalPrint\Connector /v ServicePort /d 8095 /F
            net start "print connector service"
            net start printconnectorupdatersvc
      

   3. Verify the service is listening on the new port by browsing to: http://localhost:8095/WindowsServiceHostedService/PrinterConnectorService and confirming the ProxyWCF Service page loads.

If, after these steps, the connector service continues to crash without a clear cause in the event log, collect the connector logs and open a support case, providing the event details and connector version.

References:

• Universal Print troubleshooting guide
• Universal Print Known Issues