How to fix the Oracle error ORA-12516: TNS:listener could not find available handler with matching protocol stack?

In this post, you’ll learn more about the Oracle ErrorORA-12516: TNS:listener could not find available handler with matching protocol stack with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

ORA-12516: TNS:listener could not find available handler with matching protocol stack

Reason for the Error ORA-12516: TNS:listener could not find available handler with matching protocol stack

None of the known and available service handlers for the given SERVICE_NAME support the client’s protocol stack: transport, session, and presentation protocols.

How to fix the Error ORA-12516: TNS:listener could not find available handler with matching protocol stack ?

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

Check to make sure that the service handlers (e.g. dispatchers) for the given SERVICE_NAME are registered with the listener, are accepting connections, and that they are properly configured to support the desired protocols.