ORA-12500: TNS:listener failed to start a dedicated server process
ORA-12500 TNS:listener failed to start a dedicated server process
This message indicates that the listener was unable to start a process connecting the user to the database server. The most likely cause is that the SID_LIST section of the LISTENER.ORA file or the system identifier (SID) in the CONNECT DATA section of the TNSNAMES.ORA file is incorrect. Check each of these files.
Another possible cause of this message is that the user does not have adequate privileges to access the database. Ask your database administrator to provide you access privileges if you do not have them. Also ask your system administrator to check the ownership and permissions of the database server process image.