Oracle errors

• ORA-12705: Cannot access NLS data files
• ORA-28040: No matching authentication protocol

ORA-12705: Cannot access NLS data files or invalid environment specified

The Oracle client cannot resolve the language / territory settings expected by the server. The fix is to align client regional settings with the server.

Fix:

1. Check the language the server expects. In SQL*Plus:

   SELECT userenv('LANGUAGE') FROM dual;

   A result like ENGLISH_AMERICA.WE8MSWIN1252 means the client should match American English / WE8MSWIN1252.
2. Change Windows regional settings on the DBConvert machine to match the server's territory (English / United States in the example above).
3. In SQL Developer, open Tools → Preferences → Database → NLS Parameters and set Language, Territory, and accept defaults for the rest.
4. Restart the machine for the change to take effect.

Schema: Use the SYSTEM schema rather than ANONYMOUS (which is read-only). For production work, create a dedicated schema for DBConvert with the required privileges.

For deeper diagnostics, see Troubleshooting Oracle Net Services in the Oracle documentation.

ORA-28040: No matching authentication protocol

Raised when the Oracle client and server cannot agree on an authentication protocol - usually a newer server with an older client (or vice versa) on the DBConvert machine.

Fix: install Oracle Database 12c Release 2 Client (12.2.0.1.0) for Microsoft Windows (32-bit) on the machine where DBConvert runs. Match the bitness of the DBConvert build (x86 vs x64) when installing the client.

Download: oracle12c-windows-3633015.html