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12c Windows: ORA-12518 Errors Connecting to 11g Dedicated Service Via Listener (Doc ID 2159157.1)

Last updated on MARCH 31, 2022

Applies to:

Oracle Net Services - Version to [Release 11.2 to 12.1]
Information in this document applies to any platform.
This document covers an issue that might arise only on Windows where a 12g listener is servicing connections to a pre 12 version database. This issue may not
always occur under the same set of circumstances.


The following errors are thrown in the listener log on a Windows server where a 12c version of listener is running and
servicing connections to an 11g database:


An ORA-12518 might be returned to the client.
The connection is attempted using (SERVER=DEDICATED) in the TNS Connect string.



 This is a new installation of the 12c Oracle Home.  The 12c listener is servicing connections to both 12c databases and earlier version databases.


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