ORA-12154: TNS Could Not Resolve the Connect Identifier – Complete Fix Guide

Posted on December 9, 2025December 9, 2025 by sanjeeva

The Problem: Cannot Connect to Oracle Database You’re trying to connect to your Oracle database and you get this error: When this happens: You check the database – it’s running. You check the listener – it’s up. But nothing connects. This is ORA-12154, and it means Oracle can’t find or read your TNS configuration. Let Read more about ORA-12154: TNS Could Not Resolve the Connect Identifier – Complete Fix Guide[…]

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