ORA-28546: connection initialization failed, probable Net8 admin error When using Oracle Heterogeneous Services with Oracle Release 9.2 and up, on Unix (Solaris, HP, AIX, etc.) systems, the tnsnames.ora entry may be incorrectly formatted, resulting in errors like ERROR at line 1: ORA-28546: connection initialization failed, probable Net8 admin error ORA-02068: following severe error from HSODBC ORA-03113: end-of-file on communication channel Note the following syntax, differing from that used with Oracle 9.1 and earlier, is required as of Oracle 9.2: hsodbc = (description= (address_list = (address=(protocol=tcp)(host=hostname)(port=1521)) ) (connect_data= (SID=hsodbc) ) (HS=) ) To resolve the error, edit your $ORACLE_HOME/network/admin/tnsnames.ora file to more closely resemble the above, substituting your actual values for hostname and SID as appropriate.