Setup a second extproc in the listener to point to a different set of libraries - Version 11.2.0.4

There's an existing listener extproc defined referencing a set of libraries.  I'm trying to configure a second extproc definition i.e. PLSExtProc15in the listener to reference the newer version of the libraries.

I keep getting the error "ORA-28575: unable to open RPC connection to external procedure agent" but I cannot see what this issue is.

1) listener.ora file configuration.  New definition is the PLSExtProc15.

CALL_OUT_LISTENER =

  (ADDRESS_LIST =

     (ADDRESS = (PROTOCOL = IPC) (KEY = EXTPROC0))

  )

SID_LIST_CALL_OUT_LISTENER =

  (SID_LIST =

    (SID_DESC =

      (SID_NAME = PLSExtProc)

      (ORACLE_HOME = /opt/app/oracle/product/11.2.0.4/db_1)

      (PROGRAM = extproc)

      (ENVS="EXTPROC_DLLS=ONLY:/opt/app/midlware/buildmsb27/live/bin64/libxx_test.so,/opt/app/midlware/buildmsb27/live/bin64/libxx_scrcore.a,LIBPATH=/opt/app/oracle/product/11.2.0.4/d