The specified msg.topic is not supported

I hope you can help me.
I always get this message (with every value change (update) and everything works very sluggishly in this picture!

What am I doing wrong?


There is no point posting a large flow file.

Tell us what node is generating the error and where you are seeing it.

If it is in the debug pane then it shows you the name you have given to the node. If it just shows an id number then click that and it should take you to the node.

If it is not a node-red core node then tell us which package you installed to get it.

Hi, I wanted to clear up a lot of questions with the file (already deleted)!
It's about svg graphics

In the debug area, "The specified msg.topic is not supported" is described for each


I read the temperature and write it to svg graphics using the function (thus the message is output every millisec.
As a result (I suspect) the update in the image is very sluggish.

I don't know where the problem is, even if the svg is empty without elements and pictures I get this message!

It is highly unlikely you will ever be able to push millisecond data through node-red, into a dashboard & have it update before the next value comes along.

Additionally, your monitor probably only has a 2~4ms update anyhow. Not to mention what anyone would gain by something updating every 1ms anyhow. If the value "rarely changes" then that is a LOT of wasted comms and CPU. Have you tried slimming down the data by passing it through an RBE node?

As for the "The specified msg.topic is not supported" message - what are you sending (i.e. show us what is in the message)

Lastly, I assume when you say "svg" you are refering to the node-red-contrib-ui-svg node?

Please be clear with your info and questions - it will save everyone asking and guessing :slight_smile:

In the same second 3-4 messages

yes -->node-red-contrib-ui-svg

First function
Second function
Third function

npm i node-red-node-rbe  conflict with node-red

You don't need to install the rbe node, it is included in the core nodes. It is called the Filter node now.

I've been experimenting the last few days!

I think the error is that I'm wiring the svg image with multiple functions.

If I describe two temperatures in the SVG image using two different functions!

Can someone confirm or refute this for me?

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I found out that if I select “Send only when value changes (diff)” in Konotet on S7, the warning doesn’t come!
mdg.topic is not supported

But then I have the problem when I have the dashboard open on two devices that I don't have the same status on both devices.
.json is too big and I can't post it.
Is there another possibility?


flows(13).json (86.9 KB)

That's surprising. Can you post screenshots showing the dashboard on two different devices?

The svg data included in your flow is 82600 characters long. Try starting with a simple shape and gradually building up the complexity.

if I,
“Send only when value changes (diff)”
choose then it works on all devices because it is written to it again and again, I suspect.
Then you get the warning “msg.topic is not supported”

If I,
“Send only when value changes (diff)”
Unselect then we only write once and I only see the reaction on one device in the dashboard

Please create a simple flow that exhibits the problem and post it here so that we can import it and see the problem. Use just a few nodes with Inject nodes to feed in the data.

Sorry, you didn't have time right now, I was busy with other work.

I tried to illustrate it!
I have a video about it, but I don't know how to upload it?

test.json (85.9 KB)

We don't need a video, we need a simple flow that shows the problem. Create it. Then export the flow and paste it here.

It really couldn't be that easier!
test1.json (6.7 KB)

Since I have not got an S7 that flow does not help. Replace the S7 with an inject node to inject the data. Also see this canned reply for how to post flows here inline:

In order to make code readable and usable it is necessary to surround your code with three backticks (also known as a left quote or backquote ```)

   code goes here 

See this post for more details - How to share code or flow json

I've finally arrived here!
But I haven't gotten wise yet

The problem is :
Too many descriptions of objects.

without s7 I can't reproduce it!!!