One of the most common reasons for the TNS-12516  error is the configured maximum number of PROCESSES and/or SESSIONS limitation being reached.

When this occurs, the service handlers for the TNS listener become “Blocked” and no new connections can be made.

Remember for Oracle Identity Manager 11.1.2.2.0 a minimum value for Open Cursors and Processes is required. Open Cursors 800 and Processes 500.

Try the following to to fix this error:

1.Run  “lsnrctl  service ” command to see if the service is showing up as blocked.

2. Run SQL Plus as a SYS DBA and  Increase the processes value

processes ALTER SYSTEM SET PROCESSES=500 SCOPE=SPFILE;

3. Increase the open_cursors value

open_cursors ALTER SYSTEM SET OPEN_CURSORS=500 SCOPE=SPFILE;

4.Restart the Database

5.Restart the OIM_SERVER & OIM_SERVER.