If you're on a DHCP and the IP did changed, or for some reason you tried to mess up with the hostname and changed it to something else, you wont be able to use your docbase anymore. The bad thing is, you won't see any error while loading, in fact the docbase will startup normally.
The solution was posted on Powerlink, the versions affected are Documentum 6 and Documentum 6.5, you need to download a patch on the name "pkiD6ChangeId.bat".
[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"
