Oracle Message ORA-12500 - TNS: listener failed to start a dedicated server process

ERRORTNS: listener failed to start a dedicated server process
CAUSEThe process of starting up a dedicated server process failed. The executable could not be found or the environment may be set up incorrectly.
ACTIONTurn on tracing at the ADMIN level and reexecute the operation. Verify that the ORACLE Server executable is present and has execute permissions enabled. Ensure that the ORACLE environment is specified correctly in LISTENER.ORA. The Oracle Protocol Adapter that is being called may not be installed on the local hard drive. Please check that the correct Protocol Adapter are successfully linked. If error persists, contact Oracle Customer Support.

95061Work processes die immediately after start ORA12500
81499No reconnect after offline backup
180880ORA-12500 No Cnnct poss.8.0.5 list.to 8.0.4 DB
437362Composite note ORA-12500