ORA-12505 error?

Can someone tell me what an ORA-12505 error is? I keep getting it when I try to connect with Enterprise Manager to any of the databases I've made. Connecting to the starter database works OK. I've checked everthing in SQL*NET Easy Config, but don't find anything unusual. The HTML docs don't list the error code. I'm running Server 7.3 on NT 4.0, and connecting with
NT Workstation 4.0.

As you can tell, I'm a newbie, so any help would be appreciated! :)

Thanks,
Joe Received on Mon Jun 30 1997 - 00:00:00 CDT