How to fix the Oracle error TNS-12528: TNS:listener: all appropriate instances are blocking new connections?

In this post, you’ll learn more about the Oracle ErrorTNS-12528: TNS:listener: all appropriate instances are blocking new connections with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

TNS-12528: TNS:listener: all appropriate instances are blocking new connections

Reason for the Error TNS-12528: TNS:listener: all appropriate instances are blocking new connections

Cause: All instances supporting the service requested by the client reported that they were blocking the new connections. This condition may be temporary, such as at instance startup.

How to fix the Error TNS-12528: TNS:listener: all appropriate instances are blocking new connections ?

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

Action: Attempt the connection again. If error persists, then contact the administrator to check the status of the instances.