ORA-12560: TNS:protocol adapter error

November 16, 2016

in DBA, Exceptions, ORA Errors

Sometimes you try to login to your Oracle XE on your home computer, and get this curt blocking response:

ORA-12560: TNS:protocol adapter error

Here’s the top reason why ORA-12560: TNS:protocol adapter error might occur and how to fix it.

Database is not up

The first thing to check: is the Oracle service running? If you are seeing ORA-12560:TNS protocol adapter error, the Oracle service you are trying to connect to is most likely not running.

How to check:

On a Windows machine, go to Start –> Run, type services.msc and click Enter on the keyboard.

Start Run services

This will open the Services window. Locate the service for Oracle database under the Name column – OracleServiceXE in this case. For the connection to work, the status must be "Started".

Oracle Service Status 1

As you see, the status here is NOT Started.

Start the service:

Click the link "Start" the service under the service name.

Oracle Service on Windows - Start

Once done, the status will change to Started.

Oracle Service Status Started

Try logging in next. Mission accomplished – ORA-12560:TNS protocol adapter error has vanished. You can now login.

Oracle XE Login successful


If you use this Oracle service regularly, set the service Startup Type to "Automatic". This will ensure that the database service comes up automatically whenever you restart your machine.

Also read other posts related to Oracle XE:

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