We noticed an issue with one of our Content Servers after our move to the new office a few weeks ago.  The JMS wasn’t starting up properly and we were seeing this error in the log file:

Error [DM_SESSION_E_CLIENT_AUTHENTICATION_FAILURE]error: “Could not authenticate the client installation for reason: Client hostname in authentication string doesn’t match value in registry”; ERRORCODE: 100; NEXT: null

It turns out that in both D6 and D6.5, this is a known issue – if your Content Server’s name or IP address changes, you’ll get this error.  We encountered the error because even though the server name was unchanged, the server’s IP address did change after our move to the new office.

EMC provides a tool that will fix the issue on Powerlink:

https://solutions.emc.com/emcsolutionview.asp?id=esg90932

We also updated the DCTMWiki for this error – if you solve or come across any errors, be sure to check it out the to share the knowledge:

http://dctmwiki.tsgrp.com/index.php/DM_SESSION#DM_SESSION_E_CLIENT_AUTHENTICATION_FAILURE

After applying the fix, our Content Server and JMS are working properly.  Hopefully this helps anyone else out there that’s seeing this error!