Software⏱️ 2 min read📅 2026-05-31

How to Fix ORA-28040 Error – ORA-28040: No matching authentication protocol exception

Learn how to fix: ORA-28040: No matching authentication protocol exception.

Quick Answer: Try checking your system settings or restarting.

The ORA-28040 error occurs when the authentication protocol between the Oracle database and the application server does not match. This can be caused by a mismatch in the version of the Oracle client library used to connect to the database.

🛑 Root Causes of the Error

  • The Oracle client library version does not match the version used by the database.

🛠️ Step-by-Step Verified Fixes

Method 1: Verify Oracle Client Library Version

  1. Step 1: Open the Command Prompt and run the command `oracledb -version` to check the version of the Oracle client library.

Method 2: Update Oracle Client Library

  1. Step 1: Download and install the latest version of the Oracle client library from the official Oracle website.

🎯 Final Words

By following these steps, you should be able to resolve the ORA-28040 error and connect your Grails application to the Oracle database successfully.

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❓ Frequently Asked Questions