informix rest api not startable
Sorry for the delay answer.

“OP Code is not valid: Check Message format” will happen if you are trying to connect a REST client to the Mongo wire listener. 

You need to start the listener with listener.type=rest set in your listener properties file. 

As for the same question above, there is clearly an old version of the listener being used. 

The listener is giving a very clear error message saying that the REST listener type is not supported. The REST listener was introduced in 12.10.xC4. But from the presence of the JsonListenerCLI class in the exception stack, I can determine that the installation is using a listener from either 12.10.xC2 or xC3.  The JsonListenerCLI class was renamed to ListenerCLI in 12.10.xC4 which is also the first version that include REST listener support.