[SOLUTION] - TOra "ORA-12154" Error
If you get ORA-12154 while logging to database user with TNS in TOra, this means system does not know tnsnames.ora file path.
To solve this, you can add TNS_ADMIN variable to among user variables.
e.g. C:\oraclexe\app\oracle\product\11.2.0\server\network\ADMIN
e.g. C:\orant\NET80\ADMIN
Bye.