Error Message: Tried to register a path/listener combination that is already in the model

[richard1]

I get hundreds of these error messages after starting up. What does it mean? Error is:

"Tried to register a path/listener combination that is already in the model. Value: TagSubscription(path=[default]TD23, listener=com.inductiveautomation.perspective.gateway.binding.expression.ExpressionBindingTagListener@394059fc) "

[maja]

Can somebody help with this topic?

I have the same issue. On the button, mouse event I have a script. In the script, I am asking if the tag value is different from some value if yes I am writing in that tag some another value.
Something like.
if system.tag.read(“xx”).value!=“”:
system.tag.write(“xxx”, “test”)

And on this, I have an error " [Tried to register a path/listener combination that is already in the model]. What is wrong with my expression?

[zxcslo]

Yes, this bug has been present for a long time now...

Ignition 8.0.16 - warning Tried to unregister a path/listener combination that is not present in the model

Hi in the gateway logs, if you hover over the magnifying glass to the right, it should tell you which project, view, component, and property that this error is coming from. I’ve seen this error occur when a expression binding references the same tag path more than once e.g. {tagA} + {tagA}. Therefore if you can restructure your expression to contain only one reference of the tag path, then the error would go away.

[pturmel]

Does it happen in v8.1 ? (v8.0 is end-of-life.)

[zxcslo]

Yes, in v8.1.15 too (perspective, not vision)…

[pascal.meulenkamp]

Still there in 8.1.17, I've got this on an alarm enabled binding (expression).

[Richard_Wixson]

Me too. Is this an actual bug with no fix yet or is there a workaround?

[Kevin.Herron]

Hmm, the only ticket I can find for this says it was fixed in 8.1.17. If that's not the case get in touch with support.

[robertm]

This one reared its head today.

Error is tried to register a path/listener combination that is already in the model…value: Tagsubscription(path=[xxx]metals listener = ClientSession.

This caused a total lockup of the client, but the weird thing is, this client doesn't access the tags in the log errors at all. A completely different application.

The other odd issue, is that the client that is locked up and for which the logs relate too…its IP address is not even listed in the Gateway Clients, so I cannot terminate it from the gateway.

Vision 8.1.38

[Porter_Ellis]

Still seeing this issue in my 8.1.5 edition. Any luck on the dev side? What could be causing this? This error hit my logs a few dozen times then caused the client sessions to freeze up.

[pturmel]

@Porter_Ellis

my 8.1.5 edition

Still? That version is ancient.

[Porter_Ellis]

@pturmel

Still? That version is ancient.

That is the most recent version that is non-8.3. How is that considered ancient?

[pturmel]

Ah. You must mean 8.1.50.

[Porter_Ellis]

Correct. Not 8.1.05.

[Porter_Ellis]

So with this issue being present in the newest stable version of 8.1, is there an explanation/solution?

[paul-griffith]

@Kevin.Herron

If that's not the case get in touch with support.

Your first step should be to contact support officially, so they can get an actual bug ticket going and work with you to figure out what's going wrong.

That said:

@Porter_Ellis

This error hit my logs a few dozen times then caused the client sessions to freeze up.

This particular error is almost certainly merely symptomatic of something else. What that is, I don't know, but something to do with the lifecycle management of tag subscriptions in Perspective, which is a complicated enough area that I'm sure edge cases exist. It's obviously not affecting all customers, or there would be more activity in this thread, so if you contact support there's every chance they're already familiar with a likely root cause and can help you identify or fix it.