How to fix the Oracle error ORA-12527: TNS:listener: all instances are in restricted mode or blocking new connections?

In this post, you’ll learn more about the Oracle ErrorORA-12527: TNS:listener: all instances are in restricted mode or blocking new connections with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

ORA-12527: TNS:listener: all instances are in restricted mode or blocking new connections

Reason for the Error ORA-12527: TNS:listener: all instances are in restricted mode or blocking new connections

All appropriate database instances supporting the service requested by the client reported that they either were in restricted mode or were blocking the new connections. The Listener does not allow connections to such instances. This condition may be temporary, such as at instance startup.

How to fix the Error ORA-12527: TNS:listener: all instances are in restricted mode or blocking new connections ?

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

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