Fail to connect to sql server from oracle 12c via oracle gateway

Kindly assist, am failing to DB link sql server from oracle 12c  using oracle gateway

SQL> select 1 from dual@mslink;

select 1 from dual@mslink

                   *

ERROR at line 1:

ORA-28545: error diagnosed by Net8 when connecting to an agent

Unable to retrieve text of NETWORK/NCR message 65535

ORA-02063: preceding 2 lines from MSLINK

this is how i configured the gateway ( note that the gateway software was installed in the same oracle home directory

listener.ora

=========

# listener.ora Network Configuration File: /u01/app/oracle/product/12.2.0/dbhome_1/network/admin/listener.ora

# Generated by Oracle configuration tools.

SID_LIST_LISTENER =

  (SID_LIST =

    (SID_DESC =

      (PROGRAM = /u01/app/oracle/product/12.2.0/dbhome_1/bin/dg4msql)