In a strategy running in the platform, I received this message:
MessageType : INSTRUMENT_STATUS Instument : null Tradable : false

It's not a problem because I just ignore it, but what does it mean if "null" instrument is not tradable?

This snippet of code:

    void onMessage(final IMessage message){
        // some code
            switch (message.getType()) {
                case INSTRUMENT_STATUS:
                    IInstrumentStatusMessage ism = (IInstrumentStatusMessage) message;
                    Debug.assertNotNull(ism);
                    Instrument instrument = ism.getInstrument();
                    if(instrument == null)
                        Debug.warn("Received message "+ism+" but getInstrument() == null");
                    // some code
                    break;
                // some other cases
            }
      }

...generated this output:
13:20:03 WARN: Received message MessageType : INSTRUMENT_STATUS Instument : null Tradable : false but getInstrument() == null

We could not replicate this.