How to fix the Oracle error ORA-12522: TNS:listener could not find available instance with given INSTANCE_ROLE?

In this post, you’ll learn more about the Oracle ErrorORA-12522: TNS:listener could not find available instance with given INSTANCE_ROLE with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

ORA-12522: TNS:listener could not find available instance with given INSTANCE_ROLE

Reason for the Error ORA-12522: TNS:listener could not find available instance with given INSTANCE_ROLE

There are not any available and appropriate database instances registered with the listener, that are part of the service identified by SERVICE_NAME given in the connect descriptor and that have the specified INSTANCE_ROLE (and INSTANCE_NAME, if specified).

How to fix the Error ORA-12522: TNS:listener could not find available instance with given INSTANCE_ROLE ?

You can fix this error in Oracle by following the below steps

Check to make sure that the INSTANCE_ROLE specified is correct. Run “lsnrctl services” to ensure that the instance(s) have registered with the listener and that they are ready to accept connections.