How to trace a log WARN

In the openhab.log I have a following WARN:

2023-05-30 21:36:21.699 [WARN ] [e.internal.SseItemStatesEventBuilder] - Attempting to send a state update of an item which doesn't exist: undefined
2023-05-30 21:36:23.724 [WARN ] [e.internal.SseItemStatesEventBuilder] - Attempting to send a state update of an item which doesn't exist: undefined
2023-05-30 21:37:40.784 [WARN ] [e.internal.SseItemStatesEventBuilder] - Attempting to send a state update of an item which doesn't exist: undefined
2023-05-30 21:39:56.364 [WARN ] [e.internal.SseItemStatesEventBuilder] - Attempting to send a state update of an item which doesn't exist: undefined
2023-05-30 21:39:59.280 [WARN ] [e.internal.SseItemStatesEventBuilder] - Attempting to send a state update of an item which doesn't exist: undefined

How to find where from WARN comes ?

What are you doing when this happens?

I think I usually see this when there is an Item being referenced by a MainUI Widget that doesn’t exist. The SSE is the the event stream the UI subscribes to in order to get the Item commands and updates and show the correct states of stuff on the UI.

undefined indicates that it’s a widget that uses a property or otherwise generates the Item name using an expression.

I am not doing anything.
Only sometimes will check a log file

So you never have MainUI open on any client at the times when these warning appear in the logs?

Yes, MainUI is running

Looks like there is some Widget with a wrong Itemname :slight_smile:

this is driving me mad, I looked and can’t find anything obvious is there a method to narrow it down?
it seems to warn when I click on every page, is it checking all widgets on all pages?
I do see his in the browse console log:

Setting initial tracking list: ["Hotwater_temperature","Hotwater_Booster","undefined","Daikin_Power","device1_Temperature","Daikin_Mode","Daikin_SetTemperature"]

what is “undefined” here

Somewhere you’ve got a widget where there is an expression that should evaluate to an item name that instead evaluates to undefined. The system only keeps items on the tracking list, I believe, if a page which references that item is still in the f7 app navigation history (three or so page changes back).

These items are added to the tracking list sequentially, so you can probably get a hint about which component is causing the problem by looking at where it falls in the list. Where do you have a component that uses both Hotwater_temperature and Hotwater_Booster? What components follow that one on a page or in that widget?

I usually found my problems using text-search in the .json-files (e.g. uicomponents_ui_widget.json) under …/openhab-userdata/jsondb/.