We spent the last week trying to get a new install of FMS9A Mac operational on an established 10.4.11 Server machine.
Tried all the suggestions in this and other forums but no matter how we installed the FMS9 Start Page alias on the desktop would launch the FMS9-Admin Console app but no window would appear. This would eventually time out with an error dialog "The admin console cannot establish a connection to the admin server."
As our server is running headless we couldn't try the "unplug ethernet" option as suggested in many places with similar symptoms. But I thought I'd try playing with our ethernet config.
Found that turning off all proxy settings for using our local internet cache/proxy server for internet access resolved the issue.
Believe now that there was never a Java, Caches, or Install Process involvement in our issue, and that the failure is a 'feature deficiency' where the Admin Console can't be used with proxies configured in the server's networking System Preferences.