My Oracle Support Banner

Local Connections Not Working For A DB In Windows : ORA-12560: TNS:protocol Adapter Error (Doc ID 2499416.1)

Last updated on JANUARY 29, 2020

Applies to:

Oracle Database - Enterprise Edition - Version and later
Generic Windows


Any type of connection failed with below error. 

C:\Users\xxx>sqlplus / as sysdba

SQL*Plus: Release Production on Tue Jan 15 10:24:11 2019
Copyright (c) 1982, 2013, Oracle. All rights reserved.

ORA-12560: TNS:protocol adapter error

Application connections, local connection (non sys) also impacted with same error

Window Services is up and running. Listener service also running.

All environment variables are properly set, No issue found with registry values.

Binaries permission as are properly set. 

Delete and re-creating the service also dint solved the issue. 


Windows  application log shows errors related Oracle database service. 


To view full details, sign in with your My Oracle Support account.

Don't have a My Oracle Support account? Click to get started!

In this Document

My Oracle Support provides customers with access to over a million knowledge articles and a vibrant support community of peers and Oracle experts.