Upgrade from 3.x to 4.1.RC1 (latest container version)

The Shelly binding is not working for H&T devices anymore. As far I can read this is not solved yet. Because my room temperature is based on this sensor I try to create a workaround based on MQTT.
At the moment I can read with MQTT explorer the values


So far so good.
I created a mqtt.things file

Bridge mqtt:broker:myNAS [ host="192.168.100.89", secure=false ]

Thing mqtt:topic:myNAS:mything "test mything" (mqtt:broker:myNAS) {
    Channels:
	   Type number : MQTTShellyWoonkamerHTSensorsTemperature "Huidig [%.1f °C]" [stateTopic="shellyplusht-80646fc9c5a8/status/temperature:0", transformationPattern="JSONPATH:$.tC"]
} 

and the following item

Number:Temperature MQTTShellyWoonkamerHTSensorsTemperature  "Huidig [%.1f °C]"  <temperature> (BG_Woonkamer)  ["Temperature","Measurement"] { channel="mqtt:topic:myNAS:mything:MQTTShellyWoonkamerHTSensorsTemperature" }

I don’t get a value. In the log file I read

Transformation service JSONPATH for pattern $.tC not found!

With the following I get the whole string
{“id”: 0,“tC”:22.4, “tF”:72.3}

 Type string : MQTTShellyWoonkamerHTSensorsString "Hele string"        [stateTopic="shellyplusht-80646fc9c5a8/status/temperature:0",transformationPattern="JSONPATH:$.tC"]

What is wrong?

I found the answer. I needed to install JSONPath transformation.