Environment
Retain Unified Archiving 4.x
Situation
After upgrading Retain, admin tries to access the Retain Web UI by going to http://<dnsname>/RetainServer and gets the error: This site can't be reached.
Was successfully able to access the Retain Web UI by going to http://127.0.0.1:48080/RetainServer
When attempting to access http://127.0.0.1/RetainServer, get the same error: This site can't be reached.
Resolution
Since Retain was installed on a Windows server and IIS was chosen as the web server, it was confirmed that IIS was not installed prior to the Retain upgrade.
Followed the documentation to properly install IIS. Confirmed IIS was running.
Walked through Retain installation again.
Then was able to access the Retain Web UI by going to http://<dnsname>/RetainServer