ORA-12162 TNS:net service name is incorrectly specified

"ORA-12162 TNS:net service name is incorrectly specified" misleads to verify the tnsnames.ora files for listener settings. But it's a issue with ORACLE_SID (environment variable) value.

Action: For windows: Add a environment value 'ORACLE_SID' and assign with your database name 

eg: set ORACLE_SID=orcl

For Linux: Run export ORACLE_SID=orcl or update the same in  ~/.bashrc file for permanent fix.

Note: You must also have ORACLE_HOME variable set to your Oracle database location.