How to fix the Oracle error ORA-16523: operation requires the client to connect to instance “string”?

In this post, you’ll learn more about the Oracle ErrorORA-16523: operation requires the client to connect to instance “string” with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

ORA-16523: operation requires the client to connect to instance “string”

Reason for the Error ORA-16523: operation requires the client to connect to instance “string”

The switchover or failover operation required the client to connect to the apply instance of the target database.

How to fix the Error ORA-16523: operation requires the client to connect to instance “string” ?

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

Connect to the indicated instance and reissue the SWITCHOVER or FAILOVER command.