MQTT Channel with Number Linked Item

[UPDATE] - i removed Speed from dimension on the item setting - and now also command is sent.

  • Platform information:
    • Hardware: X86_64
    • OS: Ubuntu 18.04 LTS
    • openHAB version: 2.4
      I have set MQTT channel for my Brand New Sonoff Ifan03 (tasmota)
      the IFAN accept FanSpeed topic with Values 0-3
      i created new Channel Listening on my State Topic with JSONPATH - works fine - item being update correctly upon MQTT command received.

the command topic is defined, as well.
no transformation is used… as the number should passthrough with no prefixes…

the Item linked type is Number, with Minimum Value of 0 and Max =3.
the Item Dimension is “Speed”

when i select on Paper UI a number and press “V” i get the following error in logs:

Help appreciated…

13:29:26.234 [ERROR] [rnal.common.AbstractInvocationHandler] - An error occurred while calling method 'ThingHandler.handleCommand()' on 'org.eclipse.smarthome.binding.mqtt.generic.internal.handler.GenericThingHandler@3ff5f1fa': null
java.lang.NumberFormatException: null
        at java.math.BigDecimal.<init>(BigDecimal.java:497) ~[?:?]
        at java.math.BigDecimal.<init>(BigDecimal.java:383) ~[?:?]
        at java.math.BigDecimal.<init>(BigDecimal.java:809) ~[?:?]
        at org.eclipse.smarthome.core.library.types.DecimalType.<init>(DecimalType.java:57) ~[102:org.eclipse.smarthome.core:0.10.0.oh240]
        at org.eclipse.smarthome.core.library.types.DecimalType.valueOf(DecimalType.java:71) ~[102:org.eclipse.smarthome.core:0.10.0.oh240]
        at org.eclipse.smarthome.binding.mqtt.generic.internal.values.NumberValue.update(NumberValue.java:65) ~[?:?]
        at org.eclipse.smarthome.binding.mqtt.generic.internal.generic.ChannelState.publishValue(ChannelState.java:302) ~[?:?]
        at org.eclipse.smarthome.binding.mqtt.generic.internal.handler.AbstractMQTTThingHandler.handleCommand(AbstractMQTTThingHandler.java:119) ~[?:?]
        at sun.reflect.GeneratedMethodAccessor88.invoke(Unknown Source) ~[?:?]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?]
        at java.lang.reflect.Method.invoke(Method.java:498) ~[?:?]
        at org.eclipse.smarthome.core.internal.common.AbstractInvocationHandler.invokeDirect(AbstractInvocationHandler.java:153) [102:org.eclipse.smarthome.core:0.10.0.oh240]
        at org.eclipse.smarthome.core.internal.common.InvocationHandlerSync.invoke(InvocationHandlerSync.java:59) [102:org.eclipse.smarthome.core:0.10.0.oh240]
        at com.sun.proxy.$Proxy147.handleCommand(Unknown Source) [218:org.eclipse.smarthome.binding.mqtt.generic:0.10.0.oh240]
        at org.eclipse.smarthome.core.thing.internal.profiles.ProfileCallbackImpl.handleCommand(ProfileCallbackImpl.java:75) [109:org.eclipse.smarthome.core.thing:0.10.0.oh240]
        at org.eclipse.smarthome.core.thing.internal.profiles.SystemDefaultProfile.onCommandFromItem(SystemDefaultProfile.java:49) [109:org.eclipse.smarthome.core.thing:0.10.0.oh240]
        at sun.reflect.GeneratedMethodAccessor87.invoke(Unknown Source) ~[?:?]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?]
        at java.lang.reflect.Method.invoke(Method.java:498) ~[?:?]
        at org.eclipse.smarthome.core.internal.common.AbstractInvocationHandler.invokeDirect(AbstractInvocationHandler.java:153) [102:org.eclipse.smarthome.core:0.10.0.oh240]
        at org.eclipse.smarthome.core.internal.common.Invocation.call(Invocation.java:53) [102:org.eclipse.smarthome.core:0.10.0.oh240]
        at java.util.concurrent.FutureTask.run(FutureTask.java:266) [?:?]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [?:?]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [?:?]
        at java.lang.Thread.run(Thread.java:748) [?:?]