Cause: The protocol adapter requested (by way of the “(PROTOCOL=..)” keyword-value pair in a TNS address) is unknown. If the supplied address is typographically correct then the protocol adapter is not installed.
Action: Install the protocol adapter or correct typographically error, as appropriate. Note: if the supplied address was derived from resolving the service name, check the address in the appropriate file (TNSNAMES.ORA, LISTENER.ORA or SQLNET.ORA).