i am on 2.4 correct.
its good if this is a known bug.
i will create a .thing file for each mqtt-device as long as it takes to fix.
It is fixed already. The next stable version is scheduled to come before the coming xmas ( just as if we have nothing else to do during those days☺).
hmm, and why isnt it working on my side ?
it helped me a lot - thank you hakan!
It isn’t solved on your side because you are not using a changed version. In order to get a version with changed code you would need to update now either to a snapshot or milestone version. As said before a new stable version will be released soon, if you want to stick by stable versions you could use this one.
yes, because i am a noob 
thanks for the clarification!
What we really need for any useful comment, is what is your working setup, what is your not-working setup, what does “the whole stuff breaks” look like?
raspb.3 with openhabian 2.4
bridge.things
Bridge mqtt:broker:riot "MQTT Broker"
[
host="XXXXXXXXX",
port=1883,
secure=false,
username="XXXXXX",
password="XXXXXX"
]
sonoff.things
Thing mqtt:topic:sonoff_th16 "MQTT Thing: Sonoff TH16" (mqtt:broker:riot) @ "MQTT-Things"
{
Channels:
Type switch : power "Power Switch" [
stateTopic="stat/sonoff_th16/POWER",
commandTopic="cmnd/sonoff_th16/POWER",
on="ON",
off="OFF"
]
Type string : state "Power State" [
stateTopic="stat/sonoff_th16/POWER",
on="ON",
off="OFF"
]
Type number : temperature "Temperature" [
stateTopic="tele/sonoff_th16/SENSOR",
transformationPattern="JSONPATH:$.SI7021.Temperature"
]
Type number : humidity "Humidity" [
stateTopic="tele/sonoff_th16/SENSOR",
transformationPattern="JSONPATH:$.SI7021.Humidity"
]
Type number : rssi "RSSI" [
stateTopic="tele/sonoff_th16/STATE",
transformationPattern="JSONPATH:$.Wifi.RSSI"
]
Type number : load "Load" [
stateTopic="tele/sonoff_th16/STATE",
transformationPattern="JSONPATH:$.LoadAvg"
]
Type string : uptime "Uptime" [
stateTopic="tele/sonoff_th16/STATE",
transformationPattern="JSONPATH:$.Uptime"
]
Type string : ssid "SSId" [
stateTopic="tele/sonoff_th16/STATE",
transformationPattern="JSONPATH:$.Wifi.SSId"
]
}
to here all is fine.
and as soon as i put this on the bottom of the file (sonoff.things) , both sonoffs arent showing up as Thing in PaperUI
Thing mqtt:topic:sonoff_1 "MQTT Thing: Sonoff Basic" (mqtt:broker:riot) @ "MQTT-Things"
{
Channels:
Type number : wifi "Wifi"
[
stateTopic="/Sonoff_1/WI-FI/"
]
Type number : uptime "Uptime"
[
stateTopic="/Sonoff_1/uptime/Minutes"
]
}
in 2 seperate .things files, both sonoff work as intended
I’m gonna guess openhab.log will tell you something about it when the xxx.things file is loaded.
I wonder if it has anything to do with duplicate channel ID uptime
Could you explain how you set this up with the embedded broker (Openhab Moquette, misc-mqttbroker - 2.5.1). I tried out all sorts of combinations of the bridge and things files but cannot manage to get it working. I try to send some test MQTT commands to OpenHAB via MQTT.fx first, but this does not work.
How do I setup the bridge.things file for the embedded broker? I both to use the “mqtt:systemBroker:embedded-mqtt-broker” directly in the mqtt.things file to assign a topic but also tried:
Bridge mqtt:broker:myMQTT "MQTT Broker: MyTest Mosquitto"
[
host="localhost",
port=1883,
secure=false
]
Doesn’t work 
I tried it the other way around and apparently set it up somewhat correctly, because using a trigger and this rule, I can send MQTTs and can view them in MQTT.fx
rule "MQTTtest"
when
Item mqtttest received command ON
then
val mqttActions = getActions("mqtt","mqtt:systemBroker:embedded-mqtt-broker")
mqttActions.publishMQTT("MQTT-Testtrigger","Testtest", true)
end