title: ORA-12516: TNS:listener could not find available handler with matching protocol stack
body: <p>I've been receiving these errors when I ran emca as shown below:</p>
  
  <pre><code>Dec 3, 2012 5:25:29 PM oracle.sysman.emcp.EMConfig perform
  INFO: This operation is being logged at C:\Oracle\11g\cfgtoollogs\emca\DB01\emca_2012_12_03_17_24_36.log.
  Dec 3, 2012 5:25:29 PM oracle.sysman.emcp.ParamsManager checkListenerStatusForDBControl
  WARNING: ORA-12516: TNS:listener could not find available handler with matching protocol stack
  
  Dec 3, 2012 5:25:29 PM oracle.sysman.emcp.EMConfig perform
  SEVERE:
  
  Database connection through listener failed.  Fix the error and run EM Configuration Assistant again.
  
  Some of the possible reasons may be:
  
  1) Listener port 1521 provided is incorrect.  Provide the correct port.
  2) Listener is not up.  Start the Listener.
  3) Database service DB01.world is not registered with listener.  Register the database service.
  4) Listener is up on physical host and ORACLE_HOSTNAME environment variable is set to virtual host.  Unset ORACLE_HOSTNAME environment variable.
  5) Listener is up on virtual host.  Set environment variable ORACLE_HOSTNAME=(virtual host).
  6) /etc/hosts/ does not have correct entry for hostname.
  
  Refer to the log file at C:\Oracle\11g\cfgtoollogs\emca\DB01\emca_2012_12_03_17_24_36.log for more details.
  Could not complete the configuration.  Refer to the log file at C:\Oracle\11g\cfgtoollogs\emca\DB01\emca_2012_12_03_17_24_36.log for more details.
  </code></pre>
  
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