I send the commands on MQTT explorer publish section.
I send your code:
home/OMG_multi_receiver/commands/MQTTtoPilight" -m '{"message":{\"id\":\"F15\",\"unit\":63,\"state\":\"off\"},"protocol":"clarus_switch"}'
And shows this on explorer and nothing happen on the fan:
Ok, the Publish section is split into two main areas, the topic and command message content.
Try it like this, as the examples given in the docs are the combined Mosquitto CLI sommands.
You should then also see a commands sub topic pop up on the left in your gateway’s section. Expanding it fully will reveal the command which was actually sent.
Ok, send but nothing happen:
And without the escaped nested JSON in the message?
{"message":{"id":"F15","unit":63,"state":"off"},"protocol":"clarus_switch"}
same, nothing and shows this at the left:
And maybe trying the full received message, escaped and not escaped nested message JSON
{"message": {\"id\":\"F15\",\"unit\":63,\"state\":\"off\"},"protocol":"clarus_switch","value":"","repeats":2,"status":2}
{"message":{"id":"F15","unit":63,"state":"off"},"protocol":"clarus_switch","value":"","repeats":2,"status":2}
And was the Pilight protocol the only out of the three non-rtl_433 ones which picked up the remote signals?
And what messages are being received when other remote buttons are being pressed?
When I send these commands:
{"message":{"id":"F15","unit":63,"state":"off"},"protocol":"clarus_switch"}
{"message": {\"id\":\"F15\",\"unit\":63,\"state\":\"off\"},"protocol":"clarus_switch","value":"","repeats":2,"status":2}
{"message":{"id":"F15","unit":63,"state":"off"},"protocol":"clarus_switch","value":"","repeats":2,"status":2}
PilighttoMQTT shows an error 
:
{“Status”: “Error”}
I’m going to try the other protocols 
Also, when I try other buttons, shows the same info:
{"message":{"id":"F15","unit":63,"state":"off"},"protocol":"clarus_switch","value":"","repeats":2,"status":2}
Hold on a sec …
I’ve just been told by a team mate that there is a special sending conversion for Pilight.
Could you try
{"message":{\"id\":\"F15\",\"unit\":63,\"off\":1},"protocol":"clarus_switch"}
as the JSON content?
I assume the fan is runing and we’re trying to switch it off, right?
This however is not good news, as it means the different remote buttons are not being received as different commands 
