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MGW_AGENT: mgw extproc connections fail with ORA-12537 and TNS-12518 reported in Listener log (Doc ID 2362132.1)

Last updated on FEBRUARY 12, 2020

Applies to:

Oracle Database - Enterprise Edition - Version to [Release 12.1 to 12.2]
Oracle Net Services - Version to [Release 12.1 to 12.2]
Oracle Database Cloud Schema Service - Version N/A and later
Information in this document applies to any platform.


Running an Oracle Messaging Gateway Agent (mgw_agent) out of a Database.
Using an Oracle Grid structure but single (standalone).
Upgrade was done for the GRID Home to but not the Database or Listener.

Tnsnames.ora file contains:



 This was triggered by the GRID being upgraded from to but not the Database Home.


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